Vitellogenetic defects in hybrids of the species pair Drosophila virilis and Drosophila texana

In interspecific matings between the species Drosophila virilis and Drosophila texana, female sterility can be observed in F-2 backcross females and in F-2 hybrid females. The results presented in this report show that the female sterility, whenever it exists, is due to prevention of vitellogenin synthesis in the fat body, but other abnormalities such as defects with the hybrid ovaries are not excluded. The observation that sterility appears among females from backcrosses suggests that incompatibilities between interspecific genes may cause female sterility even in the presence of a complete habloid genome from one or the other species. Yet, the parallel observation that female sterility appears only in hybrid females with recombinant chromosomes indicates that sterility results when conspecific combinations of genes on the same chromosome are broken by interspecific recombination. (C) 1996 Wiley-Liss, Inc

Ovarian defects in hybrids of the species pair Drosophila virilis and Drosophila texana

In interspecific matings between Drosophila virilis and Drosophila texana female sterility is observed in F-2 hybrid females. A previous study has shown that no vitellogenin synthesis occurs in the fat body of sterile hybrid females. The results presented in this paper show that hybrid ovaries of sterile females transplanted into the abdomens of females of the parental species are not able to develop upon maturity. With few exceptions, the hybrid ovaries remained alive in the host environment, but their oocytes failed to develop to vitellogenic stages. Thus, in hybrid females between Drosophila virilis and Drosophila texana sterility is the result of defects in both the two main developmental processes of egg maturation, the synthesis of vitellogenins in the fat body and the uptake of vitellogenins by the ovary. (C) 1997 Wiley-Liss, Inc

Biochemical and immunocytochemical analysis of vitellogenesis in the olive fruit fly Dacus (Bactrocera) oleae (Diptera : Tephritidae)

Synthesis and selective accumulation of the major yolk proteins in the developing oocytes of the species Dacus oleae (Diptera: Tephritidae) was studied biochemically and by immunoelectron microscopy. In the hemolymph of adult females, two yolk proteins precursors (or vitellogenins) have been detected. They each exhibit a similar molecular weight and isoelectric point to their respective mature yolk proteins (or vitellins), while electrophoretic analysis of their synthetic profile shows that their levels in the hemolymph increase rapidly during development. Immunogold electron microscopy of ovarian sections, revealed that the hemolymph vitellogenins reach the oocyte through enlarged inter-follicular spaces and demonstrated vitellogenin synthesis by the follicle cells of the vitellogenic follicles. The newly synthesized vitellogenins follow a distinct secretory pathway into these cells as compared to other components being synthesized at the same time (e.g. the vitelline envelope proteins), since they were found in secretory vesicles that appeared to be differentiated from those destined to participate in the vitelline envelope. The vitellogenin-containing vesicles exocytose their contents directionally into the follicle cell/vitelline envelope boundary, and subsequently the vitellogenins diffuse among the gaps of the forming vitelline envelope and reach the oocyte plasma membrane. Their internalization by the oocyte includes the formation of an endocytic complex consisting of coated pits, coated vesicles, endosomes, transitional yolk bodies, and finally mature yolk bodies, in which the storage of the vitellins and other yolk proteins occur. These results are discussed in relation to data obtained from other Dipteran species. (C) 1999 Academic Press

Incompatibilities between Y chromosome and autosomes are responsible for male hybrid sterility in crosses between Drosophila virilis and Drosophila texana

Crosses between Drosophila virilis and D. texana produce viable and fertile F-1 males and females. When F-1 males are backcrossed to either parental species they also produce fertile sons. However, about one-third of F-1 males carrying the D. texana Y chromosome are sterile. When fertile F-1 males with the D. texana Y chromosome are crossed to D. virilis, about three quarters of the sons are sterile. We show that these sterilities result from incompatibilities between the D. texana Y chromosome and at least two of the D. virilis autosomes. X/Y incompatibilities can be excluded in this pair of species, and X/autosome incompatibilities appear to be either absent or to play a minor role in the sterility of male progeny from backcrosses of F-1 males to females from either species. It is suggested that Y/autosome incompatibilities may be among the first to appear in the development of postzygotic isolation in Drosophila

Evidence for association of the rs605059 polymorphism of HSD17B1 gene with recurrent spontaneous abortions

Objective: To investigate whether the missense rs605059 polymorphism of HSD17B1 gene, which is expressed mainly in the placenta, is associated with recurrent spontaneous abortions (RSA).Methods: This study group consisted of 138 women with three or more unexplained spontaneous abortions, before the 20th week of gestation, with the same partner, while 140 healthy women served as controls. To genotype the individuals, we used the polymerase chain reaction-restriction fragment length polymorphism method.Results: The genotyping of the rs605059 polymorphism revealed the frequencies 0.22, 0.45 and 0.33, for AA, GA and GG genotypes, respectively, for the patient group and 0.37, 0.41 and 0.22, respectively, for the control group. The A allele frequencies were 0.44 and 0.57 for the patient and control group, respectively, and the G allele frequencies were 0.56 and 0.43 for the patient and control group, respectively. Statistical analysis of the results indicated the existence of significant differences in genotype and allele frequencies between the two groups.Conclusion: The rs605059 polymorphism of the HSD17B1 gene is associated with increased risk of RSA in our Caucasian Greek population. Thus it could be used as a prognostic genetic marker for RSA. © 2014 Informa UK Ltd

Modifier effect of the Glu298Asp polymorphism of endothelial nitric oxide synthase gene in autosomal-dominant polycystic kidney disease

Autosomal-dominant polycystic kidney disease (ADPKD) is one of the most common monogenic diseases. It is characterized by a substantial variability in the severity of renal phenotype, primarily assessed by the age at end-stage renal disease (ESRD). The role of modifier genes has been shown in various hereditary diseases, including ADPKD. The gene coding for the endothelial nitric oxide synthase (NOS3) is considered to have a modifier effect on the severity of ADPKD, even if there are studies among different populations that have shown contradictory results. In this study, we investigated the influence of one of the most studied polymorphisms of the NOS3 gene, the Glu298Asp polymorphism, on the age at ESRD in ADPKD. We analyzed a total of 100 ADPKD unrelated patients and 107 healthy cohorts from the Greek population. ADPKD patients were classified into two subgroups: patients with early (rapid progressors) and late (slow progressors) age at ESRD. The results suggested that the Glu298Asp polymorphism of NOS3 gene is associated with the onset age of ESRD. The distribution of C/T alleIes is significantly different between rapid and slow ADPKD progressors leading to the conclusion that the T allele of the Glu298Asp polymorphism of NOS3 gene is associated with earlier progression to ESRD in ADPKD patients. Copyright © 2008 S. Karger AG

Genetic variant in the CYP19 gene and recurrent spontaneous abortions

Background The CYP19 gene encodes aromatase, a key cytochrome P450 enzyme that converts androgens to estrogens in the ovarian tissues of premenopausal women. A polymorphic variation C/T in the CYP19 gene, rs10046, results in modified estrogen levels through increasing aromatase activity. In the present study, we investigated the possible association between the rs10046 polymorphism of the CYP19 gene and the risk of recurrent spontaneous abortions (RSA) in the Caucasian Greek population. Methods In the prospective case-control study 120 patients and 100 healthy controls were studied. Women who had at least three unexplained spontaneous abortions before 20 weeks of gestation were included in the patient group, while the control group consisted of women with at least two successful pregnancies and without history of abortions. The PCR-RFLP method was used in order to genotype the subjects. Results The frequencies of CC, CT, TT genotypes of the rs10046 variant were 0.275, 0.500, 0.225, respectively, in the patient group and 0.210, 0.480, 0.310, respectively, in the control group. The allele frequencies were 0.525 and 0.475 for C and T, respectively, in the patient group and 0.450 and 0.550 for C and T, respectively, in the control group. Statistical analysis of these results indicated that there are no significant differences in genotype (P = 0.2897) or in allele frequencies [P = 0.1261, OR (95%) = 1.351(0.9269–1.969)] between RSA patient and the control groups. Conclusion The rs10046 polymorphism of CYP19 gene seems that is not an important contributing factor in the aetiology of RSA in the Greek Caucasian population. © 2016 Elsevier Inc

Genetic variation in the HSD3B1 gene and recurrent spontaneous abortions

Objective. HSD3B1 gene encodes the 3β-hydroxysteroid deydrogenases/isomerase (3β-HSD) enzyme, which plays a crucial role in the biosynthesis of all hormonal steroids. The aim of this study was to examine the potential impact of a T → C substitution at codon Leu 338 of HSD3B1 gene on pregnancy outcome. Methods.In this prospective case-control study, 162 patients and 139 healthy controls were investigated for the possible association between the HSD3B1 T/C polymorphism and the risk of recurrent spontaneous abortions (RSA). The polymerase chain reactionrestriction fragment length polymorphism (PCRRFLP) method was used in order to genotype the subjects. Results.The frequencies of TT, TC, and CC genotypes were 0.20, 0.51, and 0.29, respectively, in the patient group and 0.20, 0.45, and 0.35, respectively, in the control group. The allele frequencies were 0.456 and 0.428 for T allele for the patient group and control group, respectively and 0.543 and 0.572 for C allele for the patient and control group, respectively. The data between the two groups were analyzed by chi-square test or Fisher's exact test. Our results showed that there are no significant differences in genotype (P = 0.56) or in allele frequencies (P = 0.51) between the patient and the control group. Conclusion.The HSD3B1 T/C polymorphism cannot be used as genetic marker for the risk for RSA in our Caucasian population. © 2012 Informa UK, Ltd

Study on the admission levels of circulating cell-free DNA in patients with acute myocardial infarction using different quantification methods

Circulating cell-free DNA (cf-DNA) is present in human biological fluids, mainly in plasma and serum, originating from cell death, a process that massively takes place during acute myocardial infarction (AMI). In the present study, cf-DNA was assessed by different quantification techniques, in order to determine its levels in patients admitted with AMI. A total of 130 subjects were included in the study: 80 ST elevation myocardial infarction (STEMI) patients and 50 healthy controls. Cf-DNA extracted from plasma was analyzed by: a) Qubit 3.0 with single (ss) and double (ds) stranded DNA assay kits, b) NanoDrop and c) quantitative PCR (qPCR). Cf-DNA levels were recorded elevated in AMI patients compared to those of healthy individuals. Specifically, Qubit 3.0 ss-DNA kit provided the highest cf-DNA concentration values for all the samples analyzed in comparison with ds-DNA assay kit and NanoDrop, approaching the values obtained by qPCR. Cf-DNA augments in massive cell death settings, including AMI, proposing that the quantification of its levels by novel methodologies could contribute to patient diagnosis and clinical management. © 2020, © 2020 Medisinsk Fysiologisk Forenings Forlag (MFFF)