Mitochondrial and microsatellite data show close genetic relationships between Dibothriocephalus latus from South America (Argentina) and Europe (the Alpine lakes region).

The most frequent causative agent of diphyllobothriosis, a fish-borne parasitic zoonosis, is the broad fish tapeworm Dibothriocephalus latus distributed mainly throughout the Holarctic region. The larval stages of the tapeworm were also detected in native and introduced freshwater fish in several lakes in South America, particularly in the north-western Patagonia in Argentina. The main objective of the present study was to determine the genetic structure of D. latus from rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta), and brook trout (Salvelinus fontinalis) from Gutiérrez Lake and Alicura Reservoir in Argentina using the sequences of three mitochondrial genes (cox1, cob, and nad3) and six polymorphic microsatellite loci. The results were compared with the corresponding molecular data of D. latus from Europe (Switzerland and Italy; the Alpine lakes region) and Asia (Siberia, Russia). Only one concatenated haplotype identical with the con-Ha1 specific for D. latus from the Alpine lakes region was detected in all individuals from Argentina. Three different alleles were detected in five out of six analysed microsatellite loci, indicating the presence of three sets of chromosomes. The same structure of microsatellite loci was recently observed in D. latus from Switzerland and Italy, in which triploidy was previously confirmed by cytogenetic study. The data on the mitochondrial genes, the allelic structure of microsatellite loci, and the principal coordinate analysis showed close genetic relationships between D. latus from Argentina and the Alpine lakes region, thus supporting the hypothesis of the European origin of the broad fish tapeworm from South America.

Ploidy influences on metabolic substrate deposition of rainbow trout

Triploid fish are usually sterile. Thus, the energy and nutrients intended for sexual maturation may be available to enhance flesh quality and physical growth. The present study aimed to investigate differences in the metabolic substrates, lipids and proteins, between storage tissues from diploid and triploid female rainbow trout. Monthly, metabolic substrates were quantified in liver, muscle, and ovaries, which were collected during the first reproductive cycle. In general, it was possible to identify a seasonal and similar deposition of metabolites in different tissues of 2n and 3n females, mainly at early stages of gonadal maturation. However, from the stages 5-6, the ovaries showed great differences between ploidies, with higher concentration of lipids and protein in 2n females. This result reflects the incorporation of vitellogenin in oocytes, which is a process that does not occur in 3n females. It was possible to observe seasonal hepato-somatic index changes in 2n females, with higher values observed in the post-ovulatory stage, and the triploid animals showed lower values compared to 2n, with no seasonal difference. Viscero-somatic index can reflect the mobilization of substrates, with higher values found for 2n females in stage 5-6, which is the period of active mobilization of tissue substrates.(AU)

Ploidy influences on metabolic substrate deposition of rainbow trout

Triploid fish are usually sterile. Thus, the energy and nutrients intended for sexual maturation may be available to enhance flesh quality and physical growth. The present study aimed to investigate differences in the metabolic substrates, lipids and proteins, between storage tissues from diploid and triploid female rainbow trout. Monthly, metabolic substrates were quantified in liver, muscle, and ovaries, which were collected during the first reproductive cycle. In general, it was possible to identify a seasonal and similar deposition of metabolites in different tissues of 2n and 3n females, mainly at early stages of gonadal maturation. However, from the stages 5-6, the ovaries showed great differences between ploidies, with higher concentration of lipids and protein in 2n females. This result reflects the incorporation of vitellogenin in oocytes, which is a process that does not occur in 3n females. It was possible to observe seasonal hepato-somatic index changes in 2n females, with higher values observed in the post-ovulatory stage, and the triploid animals showed lower values compared to 2n, with no seasonal difference. Viscero-somatic index can reflect the mobilization of substrates, with higher values found for 2n females in stage 5-6, which is the period of active mobilization of tissue substrates.

A novel PAX5 rearrangement in TCF3-PBX1 acute lymphoblastic leukemia: a case report.

BACKGROUND: Chromosome translocations are a hallmark of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Additional genomic aberrations are also crucial in both BCP-ALL leukemogenesis and treatment management. Herein, we report the phenotypic and molecular cytogenetic characterization of an extremely rare case of BCP-ALL harboring two concomitant leukemia-associated chromosome translocations: t(1;19)(q23;q13.3) and t(9;17)(p13;q11.2). Of note, we described a new rearrangement between exon 6 of PAX5 and a 17q11.2 region, where intron 3 of SPECC1 is located. This rearrangement seems to disrupt PAX5 similarly to a PAX5 deletion. Furthermore, a distinct karyotype between diagnosis and relapse samples was observed, disclosing a complex clonal evolution during leukemia progression. CASE PRESENTATION: A 16-year-old boy was admitted febrile with abdominal and joint pain. At clinical investigation, he presented with anemia, splenomegaly, low white blood cell count and 92% lymphoblast. He was diagnosed with pre-B ALL and treated according to high risk GBTLI-ALL2009. Twelve months after complete remission, he developed a relapse in consequence of a high central nervous system and bone marrow infiltration, and unfortunately died. CONCLUSIONS: To our knowledge, this is the first report of a rearrangement between PAX5 and SPECC1. The presence of TCF3-PBX1 and PAX5-rearrangement at diagnosis and relapse indicates that both might have participated in the malignant transformation disease maintenance and dismal outcome.

Karyotypic conservatism in samples of Characidium cf. zebra (Teleostei, Characiformes, Crenuchidae): Physical mapping of ribosomal genes and natural triploidy.

Basic and molecular cytogenetic analyses were performed in specimens of Characidium cf. zebra from five collection sites located throughout the Tietê, Paranapanema and Paraguay river basins. The diploid number in specimens from all samples was 2n = 50 with a karyotype composed of 32 metacentric and 18 submetacentric chromosomes in both males and females. Constitutive heterochromatin was present at the centromeric regions of all chromosomes and pair 23, had additional interstitial heterochromatic blocks on its long arms. The nucleolar organizer regions (NORs) were located on the long arms of pair 23, while the 5S rDNA sites were detected in different chromosomes among the studied samples. One specimen from the Alambari river was a natural triploid and had two extra chromosomes, resulting in 2n = 77. The remarkable karyotypic similarity among the specimens of C. cf. zebra suggests a close evolutionary relationship. On the other hand, the distinct patterns of 5S rDNA distribution may be the result of gene flow constraints during their evolutionary history.

Karyotypic conservatism in samples of Characidium cf. zebra (Teleostei, Characiformes, Crenuchidae): physical mapping of ribosomal genes and natural triploidy

Basic and molecular cytogenetic analyses were performed in specimens of Characidium cf. zebra from five collection sites located throughout the Tietê, Paranapanema and Paraguay river basins. The diploid number in specimens from all samples was 2n = 50 with a karyotype composed of 32 metacentric and 18 submetacentric chromosomes in both males and females. Constitutive heterochromatin was present at the centromeric regions of all chromosomes and pair 23, had additional interstitial heterochromatic blocks on its long arms. The nucleolar organizer regions (NORs) were located on the long arms of pair 23, while the 5S rDNA sites were detected in different chromosomes among the studied samples. One specimen from the Alambari river was a natural triploid and had two extra chromosomes, resulting in 2n = 77. The remarkable karyotypic similarity among the specimens of C. cf. zebra suggests a close evolutionary relationship. On the other hand, the distinct patterns of 5S rDNA distribution may be the result of gene flow constraints during their evolutionary history.

Karyotype and genome size of Iberochondrostoma almacai (Teleostei, Cyprinidae) and comparison with the sister-species I.lusitanicum.

This study aimed to define the karyotype of the recently described Iberian endemic Iberochondrostoma almacai, to revisit the previously documented chromosome polymorphisms of its sister species I.lusitanicum using C-, Ag-/CMA(3) and RE-banding, and to compare the two species genome sizes. A 2n = 50 karyotype (with the exception of a triploid I.lusitanicum specimen) and a corresponding haploid chromosome formula of 7M:15SM:3A (FN = 94) were found. Multiple NORs were observed in both species (in two submetacentric chromosome pairs, one of them clearly homologous) and a higher intra and interpopulational variability was evidenced in I.lusitanicum. Flow cytometry measurements of nuclear DNA content showed some significant differences in genome size both between and within species: the genome of I. almacai was smaller than that of I.lusitanicum (mean values 2.61 and 2.93 pg, respectively), which presented a clear interpopulational variability (mean values ranging from 2.72 to 3.00 pg). These data allowed the distinction of both taxa and confirmed the existence of two well differentiated groups within I. lusitanicum: one that includes the populations from the right bank of the Tejo and Samarra drainages, and another that reunites the southern populations. The peculiar differences between the two species, presently listed as "Critically Endangered", reinforced the importance of this study for future conservation plans.

Karyotype and genome size of Iberochondrostoma almacai (Teleostei, Cyprinidae) and comparison with the sister-species I. lusitanicum

This study aimed to define the karyotype of the recently described Iberian endemic Iberochondrostoma almacai, to revisit the previously documented chromosome polymorphisms of its sister species I. lusitanicum using C-, Ag-/CMA3 and RE-banding, and to compare the two species genome sizes. A 2n = 50 karyotype (with the exception of a triploid I. lusitanicum specimen) and a corresponding haploid chromosome formula of 7M:15SM:3A (FN = 94) were found. Multiple NORs were observed in both species (in two submetacentric chromosome pairs, one of them clearly homologous) and a higher intra and interpopulational variability was evidenced in I. lusitanicum. Flow cytometry measurements of nuclear DNA content showed some significant differences in genome size both between and within species: the genome of I. almacai was smaller than that of I. lusitanicum (mean values 2.61 and 2.93 pg, respectively), which presented a clear interpopulational variability (mean values ranging from 2.72 to 3.00 pg). These data allowed the distinction of both taxa and confirmed the existence of two well differentiated groups within I. lusitanicum: one that includes the populations from the right bank of the Tejo and Samarra drainages, and another that reunites the southern populations. The peculiar differences between the two species, presently listed as "Critically Endangered", reinforced the importance of this study for future conservation plans.

Long survival in a 69, XXX triploid infant in Greece

The live birth of a triploidy infant is a very rare event and death usually occurs within the first hours of life. Triploid cases with a survival of more than two months are infrequent. We report on an infant with a 69,XXX chromosome constitution who survived 164 days. Chromosomal analysis demonstrated a 69,XXX karyotype with no evidence of mosaicism. This is the longest survival reported for this condition to date in Greece and the fourth longest worldwide. The infant was admitted to our clinic several times due to respiratory problems, and supplementary oxygen was required. The improved survival of our case was possibly due to better management of respiratory illness and prematurity, and these are essential factors that physicians should consider carefully with such rare cases.