Cryopreservation: Extending the viability of biological material from sea urchin (Echinometra lucunter) in ecotoxicity tests.

The sea urchin, Echinometra lucunter, is widely used in embryo-larval tests for ecotoxicological studies in Brazil and other countries. For each test, sea urchins are collected from the wild and this can cause impact on wild populations and it is limited by the weather and season which in turn limits the ability to carry out the tests. Cryopreservation is a method of live biological material storage at low temperature and can be used for long periods with little decline in viability, reducing the number of animals taken from the wild and enabling testing to be carried out on demand, irrespective of spawning season or location. In this study, 15 combinations of cryoprotective agents (CPAs) were evaluated on spermatozoa, subjected to a rapid cooling curve followed by immersion in liquid nitrogen. Twenty-four CPA combinations were evaluated on eggs subjected to a more gradual cooling curve in nitrogen vapor down to -35 °C and then plunging in liquid nitrogen. Fertilization tests using cryopreserved spermatozoa gave high pluteus larvae yields (≈80%) when concentrations of 10.5% or 13.65% ME2SO or 13.65% ME2SO+15.75% sucrose were used. The higher concentrations of ME2SO plus sucrose were more effective at maintaining the fertilization capacity of spermatozoa post-thawing. Egg cryopreservation was not successful with 0% fertilization observed post-thawing. The results suggest that it is feasible to implement spermatozoa cryopreservation as technological innovation to create a sperm bank for E. lucunter, which can be used in ecotoxicological tests, bringing benefits for researches and contributing to the conservation of the species.

Polymorphic genetic variation in immune system genes: a study of two populations of Espirito Santo, Brazil.

Mapping single nucleotide polymorphisms (SNPs) in genes potentially involved in immune responses may help understand the pathophysiology of infectious diseases in specific geographical regions. In this context, we have aimed to analyze the frequency of immunogenetic markers, focusing on genes CD209 (SNP -336A/G), FCγRIIa (SNP -131H/R), TNF-α (SNP -308A/G) and VDR (SNP Taq I) in two populations of the Espirito Santo State (ES), Brazil: general and Pomeranian populations. Peripheral blood genomic DNA was extracted from one hundred healthy individuals of the general population and from 59 Pomeranians. Polymorphic variant identification was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). SNP genotype frequencies were in Hardy-Weinberg Equilibrium. There was no statistically significant difference in allelic and genotypic distributions between the two populations studied. Statistically significant differences were observed for SNP genotype distribution in genes CD209, TNF-α and VDR when comparing the ES populations with other Brazilian populations. This is the first report of CD209, FcγRIIa, TNF-α and VDR allelic frequencies for the general and Pomeranian populations of ES.

Analysis of genome instability in breast cancer.

Breast cancer is a heterogeneous disease, previously associated with genomic instability. Our aim was to analyze microsatellite markers in order to determine patterns and levels of instability, as well as possible correlations with histopathological parameters. Polymerase chain reaction was used to characterize microsatellite instability (MSI) and loss of heterozygosity (LOH) in 107 breast carcinomas at twelve microsatellite loci. Some of the markers were selected because of their relation to steroid hormone metabolism, which seems to be related to sporadic breast cancer risk. D5S346 and D17S250 markers showed a statistically significant frequency of MSI. LOH in D3S1611, D17S250, AR and ER-ß were associated with some parameters of worse prognosis. Marker group analysis showed that CYP19, AR and ER-ß were related to histological grade III, ER-negative and PR-negative cases. Our results suggest that marker group analysis may be preferred to the single marker strategy, being predictive of worst prognosis when single markers are unable to provide such information. A further evaluation of steroid metabolism genes and their association with low penetrance genes in breast cancer may be useful.

Polymorphism analysis of MTHFR, factor II, and factor V genes in the Pomeranian population of Espirito Santo, Brazil.

Pomeranian populations worldwide immigrated originally from the north of Europe, and because of their preferential marriage, religion, and cultural habits, they show little or no reproductive mixing with local populations. Methylenetetrahydrofolate reductase gene (MTHFR) C677T, Factor V Leiden, and Factor II G20210A polymorphisms are linked to augmented clotting and their frequencies may vary according to population ethnicity. We aimed to assess the frequencies of these thrombophilic alleles in the Pomeranian population residing in Espirito Santo and compare with the general population of the Espirito Santo state, Brazil. A total of 200 individuals were analyzed. The intrapopulation fixation index of the MTHFR C677T polymorphism was 0.03736. The observed heterozygosity was 0.44 and 0.4 for the general and Pomeranian populations, respectively. According to the chi-square test, both populations are in Hardy-Weinberg equilibrium. Four polymorphic alleles were detected for Factor II (2.02%) and 8 for Factor V (4.81%). Our results show that there is gene flow between the general and the Pomeranian population of Espirito Santo, which should no longer be considered an isolated population.

Mutation analysis of GJB2 and GJB6 genes in Southeastern Brazilians with hereditary nonsyndromic deafness.

In developed countries deafness has a genetic cause in over 60% of the cases. Contrastingly, in Brazil, it is estimated that only 16% of all deafnesses are caused by genetic factors. Among hereditary hearing deficiencies, approximately half is caused by mutations in the Gap Junction Protein Beta-2 (GJB2) gene, which encodes the protein Connexin 26 (Cx26). There are four mutations in this gene that present high prevalence in specific ethnical groups, namely, 35delG, 167delT, 235delC, and W24X. The 35delG mutation is the most frequent one, occurring in homozygosity or in compound heterozygosity with mutations in the GJB2 and GJB6 genes. This study aims to determine the prevalence of GJB2-35delG, GJB2-167delT, GJB2-235delC, GJB2-W24X, del (GJB6-D13S1830), and del (GJB6-D13S1854) mutations in patients with nonsyndromic deafness in the Espirito Santo State, Brazil. A total of 77 individuals were evaluated, from which 88.3% presented normal genotypes for all analyzed mutations, 1.3% were compound heterozygotes for 35delG-GJB2/D13S1830-GJB6, 1.3% were compound heterozygotes for 35delG/D13S1854-GJB6, 3.9% were homozygotes for the 35delG mutation and 5.2% were heterozygotes for 35delG/GJB2. The frequency of mutant alleles 35delG/GJB2, del (D13S1830/GJB6), and del (D13S1854/GJB6) was 7.8, 0.65, and 0.65%, respectively. Mutations 167delT, 235delC, and W24X were not detected. Determining the prevalence of specific mutations related to inherited deafness in a population can contribute to the development of more efficient and affordable molecular diagnostic protocols, and help in the genetic counseling of patients and their families.