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1.
Can Geriatr J ; 26(4): 478-485, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38045882

RESUMO

The virtual conference 'Transforming Care: Supporting Older Adults Post-COVID in Ontario' was held in October 2021. It was organized by Specialized Geriatric Services (SGS) East and held over three half-days. The guiding themes included: The Need, The Innovation, and The Transformation. Over 500 participants heard from ~50 clinicians, researchers, administrators, older adults, care partners, and community partners. The pandemic uncovered and exacerbated existing issues and pushed us to explore new ways to support older adults living with complex health conditions. The following key priorities were identified: older adults and their care partners call for personalized care experiences, and a lifespan approach to care delivery; aging in the community remains the most common preference; an integrated community care system that supports aging at-home should be prioritized; care delivery by SGS interprofessional teams and specialists is paramount to providing comprehensive care; building health human resource capacity should be a system priority; and promising innovations should be scaled and spread. Evidence shows that we cannot return to status-quo; post-pandemic planning of both who we serve and how we serve needs to be anchored in system renewal, not just recovery. Renewal means integrating lessons learned during the pandemic into the redesign of our systems of care. Investments in innovative, upstream strategies that support home and community-based care, and target health promotion and prevention are necessary. The provincial and regional infrastructure of SGS has the expertise and capacity to assist Ontario Health Teams in responding to the evolving health and social needs of this population.

2.
Evol Appl ; 16(6): 1220-1235, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37360025

RESUMO

Nile tilapia (Oreochromis niloticus) is among the most farmed finfish worldwide, distributed across different environmental conditions. Its wide distribution has mainly been facilitated by several breeding programs and widespread dissemination of genetically improved strains. In the first Nile tilapia study exploiting a whole-genome pooled sequencing (Poolseq) approach, we identified the genetic structure and signatures of selection in diverse, farmed Nile tilapia populations, with a particular focus on the GIFT strain, developed in the 1980s, and currently managed by WorldFish (GIFTw). We also investigated important farmed strains from The Philippines and Africa. Using both SNP array data and Poolseq SNPs, we characterized the population structure of these samples. We observed the greatest separation between the Asian and African populations and greater admixture in the Asian populations than in the African ones. We also established that the SNP array data were able to successfully resolve relationships between these diverse Nile tilapia populations. The Poolseq data identified genomic regions with high levels of differentiation (F ST) between GIFTw and the other populations. Gene ontology terms associated with mesoderm development were significantly enriched in the genes located in these regions. A region on chromosome Oni06 was genetically differentiated in pairwise comparisons between GIFTw and all other populations. This region contains genes associated with muscle-related traits and overlaps with a previously published QTL for fillet yield, suggesting that these traits may have been direct targets for selection on GIFT. A nearby region was also identified using XP-EHH to detect genomic differentiation using the SNP array data. Genomic regions with high or extended homozygosity within each population were also identified. This study provides putative genomic landmarks associated with the recent domestication process in several Nile tilapia populations, which could help to inform their genetic management and improvement.

3.
G3 (Bethesda) ; 13(3)2023 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-36639248

RESUMO

Labeo rohita (rohu) is a carp important to aquaculture in South Asia, with a production volume close to Atlantic salmon. While genetic improvements to rohu are ongoing, the genomic methods commonly used in other aquaculture improvement programs have historically been precluded in rohu, partially due to the lack of a high-quality reference genome. Here we present a high-quality de novo genome produced using a combination of next-generation sequencing technologies, resulting in a 946 Mb genome consisting of 25 chromosomes and 2,844 unplaced scaffolds. Notably, while approximately half the size of the existing genome sequence, our genome represents 97.9% of the genome size newly estimated here using flow cytometry. Sequencing from 120 individuals was used in conjunction with this genome to predict the population structure, diversity, and divergence in three major rivers (Jamuna, Padma, and Halda), in addition to infer a likely sex determination mechism in rohu. These results demonstrate the utility of the new rohu genome in modernizing some aspects of rohu genetic improvement programs.


Assuntos
Carpas , Cyprinidae , Humanos , Animais , Carpas/genética , Fluxo Gênico , Cyprinidae/genética , Tamanho do Genoma , Cromossomos
4.
Eur J Endocrinol ; 187(5): P1-P3, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36239119

RESUMO

'What's in a name? That which we call a rose/By any other name would smell as sweet.' (Juliet, from Romeo and Juliet by William Shakespeare). Shakespeare's implication is that a name is nothing but a word and it therefore represents a convention with no intrinsic meaning. Whilst this may be relevant to romantic literature, disease names do have real meanings, and consequences, in medicine. Hence, there must be a very good rationale for changing the name of a disease that has a centuries-old historical context. A working group of representatives from national and international endocrinology, nephrology and pediatric societies now proposes changing the name of 'diabetes insipidus' to 'arginine vasopressin deficiency (AVP-D)' for central etiologies and 'arginine vasopressin resistance (AVP-R)' for nephrogenic etiologies. This editorial provides both the historical context and the rationale for this proposed name change.


Assuntos
Diabetes Insípido , Diabetes Mellitus , Arginina , Arginina Vasopressina , Criança , Diabetes Insípido/terapia , Humanos
5.
Endocr J ; 69(11): 1281-1284, 2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36244744

RESUMO

"What's in a name? That which we call a rose/By any other name would smell as sweet." (Juliet, from Romeo and Juliet by William Shakespeare). Shakespeare's implication is that a name is nothing but a word and it therefore represents a convention with no intrinsic meaning. Whilst this may be relevant to romantic literature, disease names do have real meanings, and consequences, in medicine. Hence, there must be a very good rational for changing the name of a disease that has a centuries-old historical context. A working group of representatives from national and international endocrinology and pediatric endocrine societies now proposes changing the name of "diabetes insipidus" to "Arginine Vasopressin Deficiency (AVP-D)" for central etiologies, and "Arginine Vasopressin Resistance (AVP-R)" for nephrogenic etiologies. This editorial provides both the historical context and the rational for this proposed name change.


Assuntos
Arginina Vasopressina , Diabetes Insípido , Humanos , Arginina Vasopressina/deficiência , Diabetes Insípido/classificação , Diabetes Mellitus , Sociedades Médicas
6.
Endocr Connect ; 11(11)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36228658

RESUMO

'What's in a name? That which we call a rose/By any other name would smell as sweet' (Juliet, from Romeo and Juliet by William Shakespeare). Shakespeare's implication is that a name is nothing but a word, and it therefore represents a convention with no intrinsic meaning. While this may be relevant to romantic literature, disease names do have real meanings, and consequences, in medicine. Hence, there must be a very good rationale for changing the name of a disease that has a centuries-old historical context. A working group of representatives from national and international endocrinology, and pediatric endocrine societies now proposes changing the name of 'diabetes insipidus' to 'arginine vasopressin deficiency (AVP-D)' for central etiologies, and 'arginine vasopressin resistance (AVP-R)' for nephrogenic etiologies. This article provides both the historical context and the rationale for this proposed name change.

7.
Lancet Diabetes Endocrinol ; 10(10): 700-709, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36007536

RESUMO

BACKGROUND: Central diabetes insipidus is a rare neuroendocrine condition. Data on treatment-associated side-effects, psychological comorbidities, and incorrect management are scarce. The aim of this study was to investigate patients' perspectives on their disease. METHODS: This study used a cross-sectional, web-based, anonymous survey, developed by endocrinologists and patient representatives, to collect the opinions of patients with central diabetes insipidus on management and complications of their disease, psychological comorbidities, degree of knowledge and awareness of the condition among health-care professionals, and renaming the disease to avoid confusion with diabetes mellitus (diabetes). FINDINGS: Between Aug 23, 2021, and Feb 7, 2022, 1034 patients with central diabetes insipidus participated in the survey. 91 (9%) participants were children and adolescents (37 [41%] girls and 54 [59%] boys; median age 10 years [IQR 6-15]) and 943 (91%) were adults (757 [80%] women and 186 [20%] men]; median age 44 years [34-54]). 488 (47%) participants had isolated posterior pituitary dysfunction and 546 (53%) had combined anterior and posterior pituitary dysfunction. Main aetiologies were idiopathic (315 [30%] of 1034 participants) and tumours and cysts (pre-surgical 217 [21%]; post-surgical 254 [25%]). 260 (26%; 95% CI [0·23-0·29]) of 994 patients on desmopressin therapy had hyponatraemia leading to hospitalisation. Patients who routinely omitted or delayed desmopressin to allow intermittent aquaresis had a significantly lower prevalence of hyponatraemia compared with those not aware of this approach (odds ratio 0·55 [95% CI 0·39-0·77]; p=0·0006). Of patients who had to be hospitalised for any medical reason, 71 (13%; 95% CI 0·10-0·16) of 535 patients did not receive desmopressin while in a fasting state (nil by mouth) without intravenous fluid replacement and reported symptoms of dehydration. 660 (64%; 0·61-0·67) participants reported lower quality of life, and 369 (36%; 0·33-0·39) had psychological changes subjectively associated with their central diabetes insipidus. 823 (80%; 0·77-0·82) participants encountered a situation where central diabetes insipidus was confused with diabetes mellitus (diabetes) by health-care professionals. 884 (85%; 0·83-0·88) participants supported renaming the disease; the most favoured alternative names were vasopressin deficiency and arginine vasopressin deficiency. INTERPRETATION: This is the largest survey of patients with central diabetes insipidus, reporting a high prevalence of treatment-associated side-effects, mismanagement during hospitalisation, psychological comorbidities, and a clear support for renaming the disease. Our data are the first to indicate the value of routinely omitting or delaying desmopressin. FUNDING: Swiss National Science Foundation, Swiss Academy of Medical Sciences, and G&J Bangerter-Rhyner-Foundation.


Assuntos
Diabetes Insípido Neurogênico , Diabetes Insípido , Diabetes Mellitus , Hiponatremia , Adolescente , Adulto , Arginina , Criança , Estudos Transversais , Desamino Arginina Vasopressina/uso terapêutico , Diabetes Insípido/diagnóstico , Diabetes Insípido/etiologia , Diabetes Insípido Neurogênico/complicações , Diabetes Insípido Neurogênico/etiologia , Feminino , Humanos , Hiponatremia/complicações , Hiponatremia/etiologia , Internet , Masculino , Pessoa de Meia-Idade , Morbidade , Qualidade de Vida
8.
Eur J Endocrinol ; 187(3): 489-495, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35900310

RESUMO

Objective: There is growing recognition of morbidity and mortality that can occur in patients with cranial diabetes insipidus (CDI) during hospitalisation, due to prescribing errors and dysnatraemia, often related to confusion between CDI and diabetes mellitus among non-specialists. We aimed to investigate this. Methods: Data for each hospitalisation in patients with CDI attending Oxford University Hospital (OUH) were collected retrospectively. The same cohort were invited to complete a questionnaire by telephone. Results: One hundred and nine patients were included, median age was 42 (range: 6-80) years. Route of desmopressin was tablet, melt and nasal spray in 74%, 7% and 17% of patients, respectively, while two patients used a combination of tablet and nasal spray. There were 85 admissions to OUH by 38 patients between 2012 and 2021. Daily measurement of serum sodium was performed in 39% of admissions; hyponatraemia and hypernatraemia occurred in 44 and 15% of admissions, respectively. Endocrine consultation was sought in 63% of admissions post-2018. Forty-five of 78 patients (58%) self-reported ≥1 admission to any hospital since diagnosis. Of these, 53% felt their medical team did not have a good understanding of the management of CDI during hospital admission. Twenty-four per cent reported delay in administration of desmopressin, while 44% reported confusion between CDI and diabetes mellitus, often leading to unnecessary blood glucose monitoring. Conclusion: Dysnatraemia is common in hospitalised patients with CDI. More than half of patients perceived their medical team's understanding of CDI to be poor when admitted with intercurrent illness. A coordinated approach, including early consultation of specialists, frequent serum sodium monitoring, and education of hospital specialists is needed to address this.


Assuntos
Diabetes Insípido Neurogênico , Diabetes Insípido , Diabetes Mellitus , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Glicemia , Automonitorização da Glicemia , Criança , Desamino Arginina Vasopressina/uso terapêutico , Diabetes Insípido/terapia , Diabetes Insípido Neurogênico/epidemiologia , Diabetes Insípido Neurogênico/terapia , Diabetes Mellitus/epidemiologia , Humanos , Pessoa de Meia-Idade , Sprays Nasais , Percepção , Estudos Retrospectivos , Sódio , Comprimidos , Adulto Jovem
9.
JAMA Surg ; 157(7): 581-588, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35507350

RESUMO

Importance: Previous studies have suggested an association between surgical volume and patient outcomes for parathyroid surgery. However, most previous studies are relatively small and the literature is dominated by studies form the US, which might not be readily generalizable to other settings. Objective: To investigate volume-outcome associations for parathyroid surgery in England. Design, Setting, and Participants: Cohort study that included all National Health Service hospital trusts in England with secondary analysis of administrative data using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10). Participants included all adult, elective hospital admissions for parathyroid surgery without a diagnosis of multiple endocrine neoplasia, parathyroid cancer, or kidney disease over a 5-year period (April 2014-March 2019 inclusive). Exposures: The number of procedures conducted in the year prior to the index procedure by each surgeon and each hospital trust. Main Outcomes and Measures: Repeat parathyroid surgery within 1 year of the index procedure. Results: This study included data for 17 494 participants who underwent parathyroidectomies conducted across 125 hospital trusts. The median (IQR) age of patients was 62 (53-71) years, and 13 826 were female (79.0%). Across the period, the number of surgeons conducting parathyroid surgery changed little (280 in 2014-2015 and 2018-2019), although the number of procedures conducted rose from 3331 to 3848 per annum. Repeat parathyroid surgery at 1 year was significantly associated with surgeon volume (odds ratio [OR], 0.99; 95% CI, 0.98-0.99), but not trust volume, in the previous 12 months. Extended length of stay (OR, 0.98; 95% CI, 0.98-0.99), hypoparathyroidism/calcium disorder (OR, 1.0; 95% CI, 0.99-1.0), and postprocedural complications (OR, 0.99; 95% CI, 0.99-1.0) were also associated with lower surgeon volume. Conclusions and Relevance: In this cohort study, higher surgeon annual volume was associated with decreased rates of repeat parathyroid surgery. A minimum volume threshold of 20 procedures per annum should improve patient outcomes, although possible negative effects on access to services should be monitored.


Assuntos
Paratireoidectomia , Medicina Estatal , Adulto , Idoso , Estudos de Coortes , Inglaterra/epidemiologia , Feminino , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia
10.
Endocr Rev ; 43(6): 1003-1037, 2022 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-35395078

RESUMO

All endocrine glands are susceptible to neoplastic growth, yet the health consequences of these neoplasms differ between endocrine tissues. Pituitary neoplasms are highly prevalent and overwhelmingly benign, exhibiting a spectrum of diverse behaviors and impact on health. To understand the clinical biology of these common yet often innocuous neoplasms, we review pituitary physiology and adenoma epidemiology, pathophysiology, behavior, and clinical consequences. The anterior pituitary develops in response to a range of complex brain signals integrating with intrinsic ectodermal cell transcriptional events that together determine gland growth, cell type differentiation, and hormonal production, in turn maintaining optimal endocrine health. Pituitary adenomas occur in 10% of the population; however, the overwhelming majority remain harmless during life. Triggered by somatic or germline mutations, disease-causing adenomas manifest pathogenic mechanisms that disrupt intrapituitary signaling to promote benign cell proliferation associated with chromosomal instability. Cellular senescence acts as a mechanistic buffer protecting against malignant transformation, an extremely rare event. It is estimated that fewer than one-thousandth of all pituitary adenomas cause clinically significant disease. Adenomas variably and adversely affect morbidity and mortality depending on cell type, hormone secretory activity, and growth behavior. For most clinically apparent adenomas, multimodal therapy controlling hormone secretion and adenoma growth lead to improved quality of life and normalized mortality. The clinical biology of pituitary adenomas, and particularly their benign nature, stands in marked contrast to other tumors of the endocrine system, such as thyroid and neuroendocrine tumors.


Assuntos
Adenoma , Neoplasias Hipofisárias , Humanos , Neoplasias Hipofisárias/complicações , Qualidade de Vida , Adenoma/genética , Adenoma/complicações , Adenoma/metabolismo , Biologia , Hormônios
11.
Front Genet ; 12: 737906, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34616434

RESUMO

Nile tilapia is a key aquaculture species with one of the highest production volumes globally. Genetic improvement of feed efficiency via selective breeding is an important goal, and genomic selection may expedite this process. The aims of this study were to 1) dissect the genetic architecture of feed-efficiency traits in a Nile tilapia breeding population, 2) map the genomic regions associated with these traits and identify candidate genes, 3) evaluate the accuracy of breeding value prediction using genomic data, and 4) assess the impact of the genetic marker density on genomic prediction accuracies. Using an experimental video recording trial, feed conversion ratio (FCR), body weight gain (BWG), residual feed intake (RFI) and feed intake (FI) traits were recorded in 40 full-sibling families from the GIFT (Genetically Improved Farmed Tilapia) Nile tilapia breeding population. Fish were genotyped with a ThermoFisher Axiom 65 K Nile tilapia SNP array. Significant heritabilities, ranging from 0.12 to 0.22, were estimated for all the assessed traits using the genomic relationship matrix. A negative but favourable genetic correlation was found between BWG and the feed-efficiency related traits; -0.60 and -0.63 for FCR and RFI, respectively. While the genome-wide association analyses suggested a polygenic genetic architecture for all the measured traits, there were significant QTL identified for BWG and FI on chromosomes seven and five respectively. Candidate genes previously found to be associated with feed-efficiency traits were located in these QTL regions, including ntrk3a, ghrh and eif4e3. The accuracy of breeding value prediction using the genomic data was up to 34% higher than using pedigree records. A SNP density of approximately 5,000 SNPs was sufficient to achieve similar prediction accuracy as the full genotype data set. Our results highlight the potential of genomic selection to improve feed efficiency traits in Nile tilapia breeding programmes.

13.
Heredity (Edinb) ; 127(3): 334-343, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34262170

RESUMO

Enhancing host resistance to infectious disease has received increasing attention in recent years as a major goal of farm animal breeding programs. Combining field data with genomic tools can provide opportunities to understand the genetic architecture of disease resistance, leading to new opportunities for disease control. In the current study, a genome-wide association study was performed to assess resistance to the Tilapia lake virus (TiLV), one of the biggest threats affecting Nile tilapia (Oreochromis niloticus); a key aquaculture species globally. A pond outbreak of TiLV in a pedigreed population of the GIFT strain was observed, with 950 fish classified as either survivor or mortality, and genotyped using a 65 K SNP array. A significant QTL of large effect was identified on chromosome Oni22. The average mortality rate of tilapia homozygous for the resistance allele at the most significant SNP (P value = 4.51E-10) was 11%, compared to 43% for tilapia homozygous for the susceptibility allele. Several candidate genes related to host response to viral infection were identified within this QTL, including lgals17, vps52, and trim29. These results provide a rare example of a major QTL affecting a trait of major importance to a farmed animal. Genetic markers from the QTL region have potential in marker-assisted selection to improve host resistance, providing a genetic solution to an infectious disease where few other control or mitigation options currently exist.


Assuntos
Ciclídeos , Doenças dos Peixes , Tilápia , Animais , Ciclídeos/genética , Doenças dos Peixes/genética , Estudo de Associação Genômica Ampla , Locos de Características Quantitativas
14.
BMC Genomics ; 22(1): 426, 2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34107887

RESUMO

BACKGROUND: Tilapia is one of the most abundant species in aquaculture. Hypoxia is known to depress growth rate, but the genetic mechanism by which this occurs is unknown. In this study, two groups consisting of 3140 fish that were raised in either aerated (normoxia) or non-aerated pond (nocturnal hypoxia). During grow out, fish were sampled five times to determine individual body weight (BW) gains. We applied a genome-wide association study to identify SNPs and genes associated with the hypoxic and normoxic environments in the 16th generation of a Genetically Improved Farmed Tilapia population. RESULTS: In the hypoxic environment, 36 SNPs associated with at least one of the five body weight measurements (BW1 till BW5), of which six, located between 19.48 Mb and 21.04 Mb on Linkage group (LG) 8, were significant for body weight in the early growth stage (BW1 to BW2). Further significant associations were found for BW in the later growth stage (BW3 to BW5), located on LG1 and LG8. Analysis of genes within the candidate genomic region suggested that MAPK and VEGF signalling were significantly involved in the later growth stage under the hypoxic environment. Well-known hypoxia-regulated genes such as igf1rb, rora, efna3 and aurk were also associated with growth in the later stage in the hypoxic environment. Conversely, 13 linkage groups containing 29 unique significant and suggestive SNPs were found across the whole growth period under the normoxic environment. A meta-analysis showed that 33 SNPs were significantly associated with BW across the two environments, indicating a shared effect independent of hypoxic or normoxic environment. Functional pathways were involved in nervous system development and organ growth in the early stage, and oocyte maturation in the later stage. CONCLUSIONS: There are clear genotype-growth associations in both normoxic and hypoxic environments, although genome architecture involved changed over the growing period, indicating a transition in metabolism along the way. The involvement of pathways important in hypoxia especially at the later growth stage indicates a genotype-by-environment interaction, in which MAPK and VEGF signalling are important components.


Assuntos
Ciclídeos , Estudo de Associação Genômica Ampla , Animais , Ciclídeos/genética , Ligação Genética , Genótipo , Oxigênio
15.
Sci Rep ; 11(1): 11018, 2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-34040080

RESUMO

Nile tilapia is predominantly produced in smallholder ponds without aeration. We hypothesize that Nile tilapia with high oxygen uptake efficiency (O2UE) may perform better under these conditions than Nile tilapia with low O2UE. Critical swimming speed (Ucrit, in cm s-1) is a potential indicator for O2UE. Our objectives were to estimate variance components for Ucrit and fish size at swim testing early in life, and genetic correlations (rg) between Ucrit with harvest weight (HW) and daily growth coefficient (DGC) later after grow-out in a non-aerated pond. Substantial heritability was found for absolute Ucrit (0.48). The estimated rg between absolute Ucrit and fish size at testing were all strong and positive (range 0.72-0.83). The estimated rg between absolute Ucrit and HW, and absolute Ucrit and DGC were - 0.21 and - 0.63 respectively, indicating that fish with higher absolute Ucrit had lower growth in the non-aerated pond as compared to fish with lower absolute Ucrit. These results suggest a juvenile trade-off between swimming and growth performance where fish with high Ucrit early in life show slower growth later under conditions of limited oxygen availability. We conclude that Ucrit in Nile tilapia is heritable and can be used to predict growth performance.


Assuntos
Ciclídeos , Natação , Animais , Aquicultura , Peso Corporal
16.
J Anim Sci ; 99(6)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33966070

RESUMO

Feed efficiency (FE) is the amount of body weight gain for a given feed intake. Improving FE through selective breeding is key for sustainable finfish aquaculture but its evaluation at individual level is technically challenging. We therefore investigated whether individual routine metabolic rate (RMR) was a predictor of individual FE in the European sea bass Dicentrarchus labrax, a major species in European mariculture. The European sea bass has three genetically distinct populations across its geographical range, namely Atlantic (AT), West Mediterranean (WM), and East Mediterranean (EM). We compared FE and RMR of fish from these three populations at 18 or 24 °C. We held 200 fish (62 AT, 66 WM, and 72 EM) in individual aquaria and fed them from ad libitum down to fasting. FI was assessed for an ad libitum feeding rate and for a fixed restricted ration (1% of metabolic body weight·day-1, with metabolic body weight = body weight0.8). After being refed 12 wk in a common tank, individual RMR was measured over 36 h by intermittent flow respirometry. There was a significant effect of temperature whereby fish at 18 °C had greater mean FE (P < 0.05) and lower RMR (P < 0.001). There was also a significant effect of population, where AT fish had lower FE (P < 0.05) and greater RMR (P < 0.001) than WM and EM, at both temperatures. Despite these differences in temperature and population means, individual FE and RMR were not significantly correlated (P > 0.05). Therefore, although the results provide evidence of an association between metabolic rate and FE, RMR was not a predictor of individual FE, for reasons that require further investigation.


Assuntos
Bass , Animais , Aquicultura , Peso Corporal , Temperatura
19.
Front Genet ; 11: 594722, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33335540

RESUMO

Nile tilapia (Oreochromis niloticus) is among the most important finfish in aquaculture, particularly in Asia. Numerous genetically improved strains of Nile tilapia have been developed and disseminated through formal and informal channels to hatcheries, many of which operate at a relatively small scale in developing countries. The primary objective of this study was to assess the extent to which molecular genetic tools can identify different and interrelated strains of Nile tilapia in Bangladesh and the Philippines, two globally significant producers. A tool was developed using a low-density panel of single-nucleotide polymorphisms (SNPs), genotyping-by-sequencing and discriminant analysis of principal components (DAPC). When applied to 2,057 samples from 205 hatcheries in Bangladesh and the Philippines, for hatcheries where the hatchery-identified strain was one of the sampled core populations used to develop the tool, hatchery-identified and DAPC-assigned hatchery-level strains were in agreement in 74.1% of cases in Bangladesh and 80.6% of cases in the Philippines. The dominant hatchery-identified and DAPC-assigned strains were GIFT, in Bangladesh, and GET-ExCEL-a composite strain partially derived from GIFT-in the Philippines.

20.
Front Genet ; 11: 567969, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33193660

RESUMO

Domestication to captive rearing conditions, along with targeted selective breeding have genetic consequences that vary from those in wild environments. Nile tilapia (Oreochromis niloticus) is one of the most translocated and farmed aquaculture species globally, farmed throughout Asia, North and South America, and its African native range. In Egypt, a breeding program established the Abbassa Strain of Nile tilapia (AS) in 2002 based on local broodstock sourced from the Nile River. The AS has been intensively selected for growth and has gone through genetic bottlenecks which have likely shifted levels and composition of genetic diversity within the strain. Consequently, there are questions on the possible genetic impact AS escapees may have on endemic populations of Nile tilapia. However, to date there have been no genetic studies comparing genetic changes in the domesticated AS to local wild populations. This study used 9,827 genome-wide SNPs to investigate population genetic structure and signatures of selection in the AS (generations 9-11) and eight wild Nile tilapia populations from Egypt. SNP analyses identified two major genetic clusters (captive and wild populations), with wild populations showing evidence of isolation-by-distance among the Nile Delta and upstream riverine populations. Between genetic clusters, approximately 6.9% of SNPs were identified as outliers with outliers identified on all 22 O. niloticus chromosomes. A lack of localized outlier clustering on the genome suggests that no genes of major effect were presently detected. The AS has retained high levels of genetic diversity (Ho_All = 0.21 ± 0.01; He_All = 0.23 ± 0.01) when compared to wild populations (Ho_All = 0.18 ± 0.01; He_All = 0.17 ± 0.01) after 11 years of domestication and selective breeding. Additionally, 565 SNPs were unique within the AS line. While these private SNPs may be due to domestication signals or founder effects, it is suspected that introgression with blue tilapia (Oreochromis aureus) has occurred. This study highlights the importance of understanding the effects of domestication in addition to wild population structure to inform future management and dissemination decisions. Furthermore, by conducting a baseline genetic study of wild populations prior to the dissemination of a domestic line, the effects of aquaculture on these populations can be monitored over time.

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