Effects of cell concentration during cryopreservation on the post-thaw quality of Santa ines ram sperm.

BACKGROUND: Non-surgical artificial insemination techniques for sheep may benefit from larger numbers of sperm in the insemination dose because the ewe cervix is convoluted and often cannot be traversed with an insemination gun resulting in deposition of the sperm at the os cervix. OBJECTIVE: To compare a range of sperm concentrations when cryopreserving semen from Santa Ines rams and determine the effects of this on post-thaw quality. MATERIALS AND METHODS: One ejaculate from each ram (n = 10) was diluted to four sperm concentrations to obtain the following groups: G-400, G-800, G-1200, and G-1600 x 106 sperm/mL. The semen samples were packaged in 0.25 mL straws, cooled to 5 degree C, cryopreserved in liquid nitrogen vapor, thawed in a water bath (40 degree C per 20 s), and were analyzed for computerized kinetics, capacitation and acrosome integrity, and plasma membrane integrity of sperm. RESULTS: The G-400 treatment resulted in samples with the highest linearity and progressive motion (P < 0.05) and had significantly greater plasma membrane integrity, and lower capacitation and acrosome reaction rates compared to G-1600 (P < 0.05). Overall, use of the G-400 treatment resulted in better kinetics, less plasma membrane damage and less early capacitation. However, despite reducing the ejaculate yield and increasing the costs of the semen freezing process, the G-800 and G-1200 treatments make a greater absolute number of sperm with good kinetics, plasma membrane integrity and capacitation status available. CONCLUSION: Ram sperm concentration impacts cryopreservation, and higher concentrations may be advantageous if a single artificial insemination protocol is desirable. doi.org/10.54680/fr22610110812.

Origin and population structure of Brazilian hair sheep breeds.

Brazilian hair sheep constitute a genetic diversity hotspot. These animals are found in the harsh environments of the Brazilian Northwest (semi-arid) region. Genotypes (50K SNP chip) from seven Brazilian sheep breeds (five hair and two coarse wool types) and 87 worldwide breeds were used to test for population structure, admixture and genetic diversity. Moreover, phylogenetic trees evaluating migration events between genetic groups were built. Brazilian Somali, a fat-tailed breed, had a close relationship with East African breeds and clustered distinctly from other Brazilian breeds. Brazilian Blackbelly and Barbados Blackbelly had a close relationship. The Morada Nova breed did not show close relationships with European or African breeds, revealing a single migration event from an Algerian hair breed. Brazilian Fat-tail and Morada Nova share a common ancestor, but the former showed introgressions from Brazilian Somali and Afrikaner breeds, explaining the fat-tail phenotype. The Santa Inês breed received a substantial contribution from Brazilian Bergamasca and showed an admixed origin with recent introgressions from other breeds, mainly from Suffolk. Furthermore, Brazilian Somali and Brazilian Fat-tail are the most endangered sheep genetic resources in Brazil and should be the focus for ex situ conservation programs. In conclusion, Brazilian hair sheep show an African origin and are characterized by diverse genetic composition, reinforcing the need for conservation of these genetic resources, and at the same time, this highly diverse group has variability that can be used in breeding programs.

Evaluation of morphology, morphometry and follicular dynamics in FecGE genotyped ewes.

This study aimed to evaluate the effect of FecGE mutation on the development of ovarian follicles. To this end, 42 Santa Inês ewes were genotyped for FecGE mutation and classified as wild-type (FecG+/+), heterozygous (FecG+/E) or mutant homozygous (FecGE/E). Ovarian fragments were processed, and the follicles were analyzed with regard to the morphology and morphometry using classical histology. For the evaluation of follicular dynamics, ewes underwent oestrous synchronization and were monitored throughout an interovulatory period. A higher (P < 0.05) percentage of morphologically normal follicles in the primordial stage was identified in FecGE/E (90.0%) and FecG+/E (88.1%) ewes than in the FecG+/+ (73.0%) ewes. There was also a significantly greater (P < 0.05) number of morphologically normal follicles in the FecGE/E (87.3%) and FecG+/E (83.3%) ewes than in FecG+/+ (76.8%) ewes in the transitional stage. A smaller (P < 0.05) diameter was observed in the secondary follicles in FecGE/E (93.8 µm) ewes than in FecG+/E (171.8 µm) ewes. Regarding follicular dynamics, FecGE/E ewes showed a greater (P < 0.05) number of ovulations (2.5 ±â€¯0.2) than FecG+/+ ewes (1.5 ±â€¯0.3) ewes. Ovulatory follicles were smaller (P < 0.05) in the FecGE/E (5.1 mm) and FecG+/E (5.2 mm) ewes than in FecG+/+ (5.8 mm) ewes. Santa Inês nulliparous ewes carrying the FecGE mutation showed a greater proportion of morphologically normal follicles in the primordial and transitional stages than those not carrying the mutation. FecGE/E ewes demonstrated a higher number of ovulated follicles and that FecGE/E and FecG+/E ewes presented ovulatory follicles with a smaller diameter.

Single nucleotide polymorphisms in the growth hormone and IGF type-1 (IGF1) genes associated with carcass traits in Santa Ines sheep.

Polymorphisms in the growth hormone (GH) and IGF type-1 (IGF1) genes have been associated with the economic traits in farm animals, including BW of some sheep breeds. However, it remains unknown if these polymorphisms also affect carcass traits in sheep. Thus, we aimed to identify polymorphisms in the GH and IGF1 genes in Santa Ines sheep in order to describe their allelic and genotypic frequencies as well as to test the hypotheses that they are associated with the carcass traits. Fragments of 4550 bp (IGF1) and 1194 bp (GH) were sequenced in up to 191 lambs. In all, 18 polymorphisms were identified in the IGF1 and 21 in the GH gene. The IGF1 polymorphisms rs430457475, rs412470350, rs409110739 and rs400113576 showed an additive effect on the internal carcass length (-0.9265±0.4223), rump girth (-2.9285±1.1473), rib yield (-1.0003±0.4588) and neck weight (-0.0567±0.0278), respectively. In addition, the polymorphisms rs58957314 in the GH affected the rib weight (-0.4380±0.1272) and rib yield (-2.2680±0.6970), loin weight (-0.1893±0.0516) and loin yield (-0.9423±0.3259), palette weight (-0.2265±0.0779) and palette yield (-0.9424±0.4184), leg weight (-0.3960±0.1375), neck weight (-0.0851±0.0394) and carcass finishing score (-0.1700±0.0839). These results allow us to conclude that there are polymorphisms in the IGF1 and GH genes associated with carcass traits in Santa Ines sheep, which can provide important information for marker-assisted selection.

Use of aqueous extract of noni in extender for sheep semen freezing / Utilização do extrato aquoso de noni em diluente para congelação de sêmen ovino

The study aimed to evaluate the action of aqueous extract of noni in an extender for sheep semen freezing. Treatments differed in inclusion of aqueous extract of noni in the extender: T1 ˗ no addition; T2 ˗ 24µg/mL; T3 ˗ 72µg/mL; and T4 ˗ 120µg/mL. Ejaculates were collected, diluted in the four treatments, and frozen. After thawing, the semen was subjected to a thermoresistance test and evaluated for subjective motility, vigor, membrane integrity assessment by hypo-osmotic swelling test, live-dead assay, computer-assisted sperm analysis and the status of sperm capacitation and acrosome reaction. Data were subjected to ANOVA, and then to Student Newman Keuls's test at 5% significance level. In the thermoresistance test after two hours of incubation, motility in T4 (120µg/mL) was lower than in the other treatments, with no differences in the HoS test in either diluted semen or in the semen evaluated immediately post-thawing, while for the other times, treatments showed similar responses. Regarding the motility parameters, a difference was observed for progressive motility, curvilinear velocity, average path velocity, and amplitude of lateral head displacement. As to the sperm capacitation status, a difference was observed between treatments for the sperm capacitated with intact acrosome.(AU)

Este estudo teve como objetivo avaliar a ação do extrato aquoso de noni em diluente para congelação de sêmen de carneiro. Os tratamentos diferiram quanto à inclusão de extrato aquoso de noni ao meio diluidor em: T1˗ sem adição de extrato; T2˗ 24µg/mL ; T3- 72µg/mL e 120µg/mL. Por meio de vagina artificial, 16 ejaculados foram coletados, diluídos entre os quatro tratamentos e congelados. Após o descongelamento, o sêmen foi submetido ao teste de termorresistência e avaliado quanto à motilidade subjetiva, ao vigor espermático, à integridade de membrana pelo teste hiposmótico, bem como ao teste supravital, à análise de sêmen assistida por computador (CASA) e ao status de capacitação espermática e de reação acrossomal. Os dados foram submetidos a uma análise de variância, seguida pelo teste de Student-Newman-Keuls com 5% de significância. No teste de termorresistência, após duas horas de incubação, a motilidade do T4 (120µg/mL) apresentou-se inferior aos demais tratamentos. Não houve diferença significativa no teste HOS tanto para o sêmen diluído quanto para o sêmen avaliado imediatamente pós-descongelação; para as demais horas, os tratamentos apresentaram comportamento semelhante. Para os parâmetros de cinética, foi observada diferença estatística para motilidade progressiva, velocidade curvilinear, velocidade do percurso médio e amplitude de deslocamento lateral da cabeça. Quanto ao estado de capacitação espermática, observou-se diferença entre os tratamentos para espermatozoide capacitado com acrossomo intacto.(AU)

In vitro chondrogenic commitment of human Wharton's jelly stem cells by co-culture with human articular chondrocytes.

Wharton's jelly stem cells (WJSCs) are a potential source of transplantable stem cells in cartilage-regenerative strategies, due to their highly proliferative and multilineage differentiation capacity. We hypothesized that a non-direct co-culture system with human articular chondrocytes (hACs) could enhance the potential chondrogenic phenotype of hWJSCs during the expansion phase compared to those expanded in monoculture conditions. Primary hWJSCs were cultured in the bottom of a multiwell plate separated by a porous transwell membrane insert seeded with hACs. No statistically significant differences in hWJSCs duplication number were observed under either of the culture conditions during the expansion phase. hWJSCs under co-culture conditions show upregulations of collagen type I and II, COMP, TGFß1 and aggrecan, as well as of the main cartilage transcription factor, SOX9, when compared to those cultured in the absence of chondrocytes. Chondrogenic differentiation of hWJSCs, previously expanded in co-culture and monoculture conditions, was evaluated for each cellular passage using the micromass culture model. Cells expanded in co-culture showed higher accumulation of glycosaminoglycans (GAGs) compared to cells in monoculture, and immunohistochemistry for localization of collagen type I revealed a strong detection signal when hWJSCs were expanded under monoculture conditions. In contrast, type II collagen was detected when cells were expanded under co-culture conditions, where numerous round-shaped cell clusters were observed. Using a micromass differentiation model, hWJSCs, previously exposed to soluble factors secreted by hACs, were able to express higher levels of chondrogenic genes with deposition of cartilage extracellular matrix components, suggesting their use as an alternative cell source for treating degenerated cartilage. Copyright © 2015 John Wiley & Sons, Ltd.

Fish sperm subpopulations: Changes after cryopreservation process and relationship with fertilization success in tambaqui (Colossoma macropomum).

Fish tambaqui (Colossoma macropomum) is the native Brazilian fish with the highest agricultural production under intensive aquaculture in South America. However, the decrease in the genetic variability in fish farms has become necessary the improvement of cryopreservation process through new statistical studies of spermatozoa (like subpopulation studies). The evaluation of the kinetic data obtained with a computer-assisted sperm analysis system, applying a two-step cluster analysis, yielded in tambaqui three different subpopulations in fresh sperm: SP1, considered as a slow nonlinear subpopulation; SP2, considered as a fast nonlinear subpopulation, and finally; SP3, considered as a fast linear subpopulation. For cryopreserved sperm, the cluster analysis yielded only two sperm subpopulations: SP1', considered as a slow nonlinear subpopulation and SP2', which seemed to be an intermediate subpopulation (showing medium motility and velocity values) merged from SP2 and SP3 obtained from fresh sperm. Coefficients of correlation (r) and determination (r2) between the sperm subpopulations from fresh sperm and the fertilization rates were calculated, and SP2 and SP3 (the fast-spermatozoa subpopulations) showed a high-positive correlation with the fertilization rates (r = 0.93 and 0.79, respectively). In addition, the positive significant correlations found in curvilinear velocity (r = 0.78), straight line velocity (r = 0.57), and average velocity (r = 0.75) indicate that sperm kinetic features seem to be a key factor in the fertilization process in tambaqui, as occur in other fish species.

Genetic diversity of the forage peanut in the Jequitinhonha, São Francisco, and Paranã River valleys of Brazil.

Arachis pintoi and A. repens are legumes with a high forage value that are used to feed ruminants in consortium systems. Not only do they increase the persistence and quality of pastures, they are also used for ornamental and green cover. The objective of this study was to analyze microsatellite markers in order to access the genetic diversity of 65 forage peanut germplasm accessions in the section Caulorrhizae of the genus Arachis in the Jequitinhonha, São Francisco and Paranã River valleys of Brazil. Fifty-seven accessions of A. pintoi and eight of A. repens were analyzed using 17 microsatellites, and the observed heterozygosity (HO), expected heterozygosity (HE), number of alleles per locus, discriminatory power, and polymorphism information content were all estimated. Ten loci (58.8%) were polymorphic, and 125 alleles were found in total. The HE ranged from 0.30 to 0.94, and HO values ranged from 0.03 to 0.88. By using Bayesian analysis, the accessions were genetically differentiated into three gene pools. Neither the unweighted pair group method with arithmetic mean nor a neighbor-joining analysis clustered samples into species, origin, or collection area. These results reveal a very weak genetic structure that does not form defined clusters, and that there is a high degree of similarity between the two species.

Taxa de fertilidade de novilhas de diferentes grupos genéticos com primeiro serviço aos 14 meses de idade / Fertility rate of heifers of different genetic groups with 1st service at 14 months of age

Foram avaliadas as taxas de reconcepção de 98 novilhas primíparas (34 Guzerá - G, 32, 1/2 Guzerá x 1/2 Nelore - GN e 32,1/2 Red Angus x 1/2 Nelore - AN) com 14 meses de idade e peso médio de aproximadamente 249,65kg, criadas em pastos de Brachiaria brizantha cv Marandu. Na segunda estação de monta (EM), foram utilizadas apenas as 36 primíparas gestantes na primeira EM (três G, nove GN e 24 AN), com média de idade de 26 meses e peso corporal de 313,67±25,01kg, 336,50±45,84kg e 399,86±44,45kg, respectivamente, para as fêmeas dos grupos G, GN e AN. O grupo AN apresentou ganho médio diário (GMD) de 0,30±0,06 (kg/dia) e maiores taxas (58,33) de reconcepção (P<0,05), comprovando que a heterose resultante do cruzamento entre raças distintas com maior distância genética (Bos taurus taurus x Bos taurus indicus) proporciona maior desempenho produtivo e reprodutivo.

A total of 98 heifers of three genetic groups: 34 Guzerá (G), 32, 1/2 Guzerá x 1/2 Nelore (GN) and 32 1/2 Red Angus x 1/2 Nelore (AN), 14 month old and average body weight of 249,65kg, raised in Brachiaria brizantha cv Marandu were used to evaluate reconception rates. In the second breeding season (BS), only those 36 pregnant in the first BS (three G, nine GN and 24 AN), age 26 months and body weight of 313.67±25.01kg, 336.50±45.84kg and 399.86±44.45kg, respectively, G , GN and AN were evaluated. The highest reconception rate (58.33%, P<0.05) was registered for the AN group and showed that average daily gain of 0.30±0.06kg, showing that crosses between Bos taurus taurus x Bos taurus indicus leads to higher reproductive and productive performances.

Effects of acute aerobic exercise on leukocyte inflammatory gene expression in systemic lupus erythematosus.

UNLABELLED: Systemic lupus erythematosus (SLE) is an autoimmune disease with a persistent systemic inflammation. Exercise induced inflammatory response in SLE remains to be fully elucidated. The aim of this study was to assess the effects of acuteexercise on leukocyte gene expression in active (SLEACTIVE) and inactive SLE (SLEINACTIVE) patients and healthy controls(HC). METHODS: All subjects (n = 4 per group) performed a 30-min single bout of acute aerobic exercise (~70% of VO2peak) on a treadmill, and blood samples were collected for RNA extraction from circulating leukocyte at baseline, at the end of exercise, and after three hours of recovery. The expression of a panel of immune-related genes was evaluated by a quantitative PCR array assay. Moreover, network-based analyses were performed to interpret transcriptional changes occurring after the exercise challenge. RESULTS: In all groups, a single bout of acute exercise led to the down-regulation of the gene expression of innate and adaptive immunity at the end of exercise (e.g., TLR3, IFNG, GATA3, FOXP3, STAT4) with a subsequent up-regulation occurring upon recovery. Exercise regulated the expression of inflammatory genes in the blood leukocytes of the SLE patients and HC, although the SLE groups exhibited fewer modulated genes and less densely connected networks (number of nodes: 29, 40 and 58; number of edges: 29, 60 and 195; network density: 0.07, 0.08 and 0.12, for SLEACTIVE, SLEINACTIVE and HC, respectively). CONCLUSION: The leukocytes from the SLE patients, irrespective of disease activity, showed a down-regulated inflammatory geneexpression immediately after acute aerobic exercise, followed by an up-regulation at recovery. Furthermore, less organized gene networks were observed in the SLE patients, suggesting that they may be deficient in triggering a normal exercised-induced immune transcriptional response.

Ganho compensatório no desempenho e eficiência econômica de novilhos Nelore submetidos a diferentes regimes alimentares / Compensatory gain in performance and economic efficiency of Nellore steers under different feeding regimes

Avaliaram-se o efeito do ganho compensatório no desempenho produtivo e a eficiência econômica de novilhos submetidos a diferentes estratégias de suplementação alimentar na fase de recria e engorda. Cinquenta e quatro bezerros, com peso médio inicial de 169,6±16,7kg, foram divididos em oito tratamentos, sendo cada tratamento uma estratégia de suplementação alimentar. No período da seca, os animais receberam suplemento proteico-energético-mineral (SP), com ingestão média diária de 0,1 ou 0,2% do peso vivo. No período das águas, os novilhos receberam SP com ingestão média diária de 0,5% do peso vivo ou suplementação mineral (SM). No período de terminação, os animais receberam SP com ingestão média diária de 1,4% do peso vivo ou foram confinados. Os animais que receberam SM não tiveram ganho compensatório. Animais que receberam SP nas águas (0,51±0,07kg/dia) tiveram ganho compensatório em relação ao período anterior e obtiveram ganho adicional diário de 123g quando comparados com SM (0,39±0,07kg/dia), entretanto não obtiveram ganho compensatório na fase de terminação. O efeito do ganho compensatório é muito pequeno ou até mesmo nulo no sistema de recria e engorda precoce com terminação em confinamento. A suplementação com menor ingestão de proteína, energia e mineral durante a primeira seca e águas, pós-desmame, da vida de novilhos pode ser compensada com o uso do confinamento na fase de terminação desses animais com resultados econômicos positivos.

The effect of compensatory growth on performance and economical efficiency of steers on different dietary supplementation strategies in the rearing and fattening stages was evaluated. Fifty-four calves with average initial weight of 169.6±16.7kg were divided into eight treatments, each of them being a strategy of food supplementation. During the dry season the animals received protein - energy - mineral supplement (SP) with an average daily intake of 0.1 or 0.2 % of body weight (BW). During the rainy season the animals received SP with an average daily intake of 0.5 % of body weight or mineral supplementation (SM). In the fattening period, the animals received SP with an average daily intake of 1.4 % of body weight or were placed in feedlot. Animals that received SM had no compensatory gain. Animals that received SP during the rainy season (0,51±0,07kg/day) had compensatory growth when compared to the previous period, and obtained additional daily gain of 123g when compared to SM group (0,39±0,07kg/day), however did not obtain compensatory gain during the fattening phase. The effect of compensatory gain becomes minimal or zero in feedlot finished. Supplementation strategies with protein, energy and mineral intake in the first dried and the first water in steer's life can be compensated with the use of these animals in the feedlot finishing phase with positive economic results.

Long-term globular adiponectin administration improves adipose tissue dysmetabolism in high-fat diet-fed Wistar rats.

Adiponectin administration to obese or type 2 diabetic patients is still far off, due to its expensive costs and absence of studies demonstrating the effectiveness of its chronic administration. We performed long-term globular adiponectin administration, testing its usefulness in improving adipose tissue metabolism. Adiponectin (98 υg/day) was administered through a subcutaneous minipump with continued release (28 days) to Wistar rats fed a high-fat diet. Adiponectin decreased body weight and adipocyte size, while decreasing circulating leptin levels. More, adiponectin was able to increase IkappaBalpha and PPARgamma levels and to prevent high-fat diet-induced impairment of insulin signalling, especially in epididymal adipose tissue. This resulted in improved glucose profile. High-fat diet caused an impairment of lipolysis in epididymal adipose tissue, which was partially restored by adiponectin treatment. Long-term globular adiponectin administration was able to improve pathways of insulin signalling and lipid storage in adipose tissue of high-fat diet-fed rats, contributing to a better metabolic profile.

Fabrication of phospholipid-xanthan microcapsules by combining microfluidics with self-assembly.

We report the synthesis of an amphiphilic polysaccharide, a phospholipid (1,2-dioleoyl-sn-glycero-phosphoetilamine, DOPE) conjugated with the anionic xanthan gum, and its ability to spontaneously self-assemble under mild aqueous conditions. This work also aimed to apply a microfluidic platform that can precisely fabricate microsized and monodispersed capsules for cell encapsulation. Stable hollow capsular structures were obtained by the generation of homogeneous spherical droplets of the self-assembled polymer in the microfluidic device through the formation of a water-in-oil emulsion, followed by the stabilization of the polymer aggregates in a separate collection vessel containing phosphate-buffered saline (physiological ionic strength and pH). The properties (size, morphology, permeability) and performance (stability) of the obtained microcapsules were studied, as well their ability to support the viability, function and proliferation of encapsulated cells. ATDC5 cells were encapsulated within the capsules and shown to remain viable, evidencing increased cellular metabolic activity over 21 days of in vitro culture. By combining microfluidic droplet generation and self-assembly of xanthan-DOPE, we were able to fabricate microcapsules that provided an adequate environment for cells to survive and proliferate.

Cryopreservation of tambaqui (Colossoma macropomum) semen: extenders, cryoprotectants, dilution ratios and freezing methods.

The tambaqui is an Amazonian fish of great economic and environmental importance to Brazil and other South American countries. Several semen cryopreservation methodologies have been tested for different Brazilian fish species; however, there is little information on the use of this technique on tambaqui semen. The aim of the present study was to investigate the effect of osmolarity and activation solutions on sperm kinetics and, glucose solutions, cryoprotectants, dilution ratios, egg yolk and freezing methods on tambaqui semen freezing. The osmolarity of 230 mOsm was suitable for simultaneously yielding higher sperm motility (85%) and motility time (54 sec.) and osmolarities above 360 mOsm maintain immobile tambaqui sperm. The tambaqui semen can be successfully cryopreserved when diluted 1:9 in freezing medium composed of 5 percent glucose solution (290 mOsm) with 10 percent methylglycol and 5 percent egg yolk, and frozen directly in a dry shipper container.

Genetic diversity and assessment of 23 microsatellite markers for parentage testing of Santa Inês hair sheep in Brazil.

Santa Inês is the most common hair sheep breed in Brazil and probably has the highest genetic diversity among sheep breeds in this country. Successful breeding programs for Brazilian sheep breeds are not common for various reasons, including a lack of control of parentage in the flocks. We developed an allele frequency database for 23 STR loci for the Santa Inês breed based on 285 animals sampled from five populations distributed across the central-western and north-eastern regions of Brazil. The marker set included seven microsatellites used in the 2011 International Society for Animal Genetics sheep genotyping comparison tests and all eight microsatellites currently approved by the Brazilian Agricultural Ministry laboratory accreditation guidelines for sheep identification. The microsatellites had an average of 10 alleles and a mean expected heterozygosity of 0.745. Combined paternity exclusion probabilities when no parent or one parent was known were >99.99%. A small proportion (5.8%) of the existing genetic variation was found to be among the Santa Inês populations, possibly derived from genetic drift and selection. We found that the marker panel proposed by the Agricultural Ministry, although generally useful, should be enhanced by including more markers for improved exclusionary power in parentage testing. This database provides a useful tool for parentage testing of this major Brazilian breed, contributing to improved management and breeding of existing herds.

Injectable biodegradable starch/chitosan delivery system for the sustained release of gentamicin to treat bone infections.

Starch-conjugated chitosan microparticles were produced aimed to be used as a carrier for the long term sustained/controlled release of antibiotic drugs to control bone infection. The microparticles were prepared by a reductive alkylation crosslinking method. The obtained microparticles showed a spherical shape, with a slightly rough and porous surface, and a size range of 80-150µm. Gentamicin was entrapped into the starch-conjugated chitosan microparticles and its release profile was studied in vitro. Increasing concentrations of gentamicin (from 50 to 150mg/mL) led to a decrease in the encapsulation efficiency (from 67 to 55%), while drug loading increased from 4 to 27%. A sustained release of gentamicin was observed over a period of 30 days. The release kinetics could be controlled using an ionic crosslinker agent. In addition, a bacterial inhibition test on Staphylococcus aureus shows a diameter of the sample inhibition zone ranging from 12 to 17mm (70-100% of relative activity).

Genotoxicity of SPL (spent pot lining) as measured by Tradescantia bioassays.

Spent Pot Liner (SPL) is a solid waste product generated in the process of aluminum production. Tradescantia micronuclei (Trad-MN) and stamen hair mutation (Trad-SHM) bioassays are very useful tests to assess genotoxicity of environmental pollutants. In the present study, we intended to investigate the genotoxicity of this waste with Tradescantia bioassays using leachates of SPL simulating the natural leachability of SPL in soil. The formation of micronuclei (MN) was found to be concentration dependent. MN frequency enhanced significantly with SPL treatment. In addition, SPL also appeared to increase the percentage of dyads and triads. Trad-SHM assay showed that SPL increases pink mutation events as SPL concentration increases. These results demonstrated that SPL is a cytogenotoxic agent that affects different genetic end-points (induction of micronuclei and point mutations) even at low concentration (2% and 3%).

A new polymorphism in the Growth and Differentiation Factor 9 (GDF9) gene is associated with increased ovulation rate and prolificacy in homozygous sheep.

Brazilian Santa Inês (SI) sheep are very well-adapted to the tropical conditions of Brazil and are an important source of animal protein. A high rate of twin births was reported in some SI flocks. Growth and Differentiation Factor 9 (GDF9) and Bone Morphogenetic Protein 15 (BMP15) are the first two genes expressed by the oocyte to be associated with an increased ovulation rate in sheep. All GDF9 and BMP15 variants characterized, until now, present the same phenotype: the heterozygote ewes have an increased ovulation rate and the mutated homozygotes are sterile. In this study, we have found a new allele of GDF9, named FecG(E) (Embrapa), which leads to a substitution of a phenylalanine with a cysteine in a conservative position of the mature peptide. Homozygote ewes presenting the FecG(E) allele have shown an increase in their ovulation rate (82%) and prolificacy (58%). This new phenotype can be very useful in better understanding the genetic control of follicular development; the mechanisms involved in the control of ovulation rate in mammals; and for the improvement of sheep production.

Silk fibroin microparticles as carriers for delivery of human recombinant BMPs. Physical characterization and drug release.

Bone morphogenetic proteins (BMPs) are cytokines with strong ability to promote new bone formation. Herein, we report the use of silk fibroin microparticles as carriers for the delivery of BMP-2, BMP-9 or BMP-14. BMP-containing fibroin microparticles were prepared by a mild methodology using dropwise addition of ethanol, exhibiting mean diameters of 2.7 +/- 0.3 microm. Encapsulation efficiencies varied between 67.9 +/- 6.1 % and 97.7 +/- 2.0 % depending on the type and the amount of BMP loaded. Release kinetics showed that BMP-2, BMP-9 and BMP-14 were released in two phases profile, with a burst release in the first two days followed by a slower release, for a period of 14 days. The release data were best explained by Korsmeyer's model and the Fickian model of drug diffusion. Silk fibroin microparticles can offer a promising approach for the sustained delivery of different BMPs in tissue engineering applications.