Spermatogenesis refers to the developmental process of male germ cell formation from the spermatogonial stem cell to mature spermatozoa. The progression of male germ cells through the different phases of development, along with changes in cellular size and morphology, involves a coordinated change in their gene expression program at both the transcript and protein levels. It is well known that the stability, biological activity and cellular localization of proteins are regulated by post-translational modifications. In this review, we provide a brief update of current knowledge about the role of protein acetylation in mammalian spermatogenesis. Based on recent findings specific examples were cited to illustrate how these modifications are involved in controlling the different events that are important to the proper development of male germ cells.
Background: Observations of increasing asthma incidence, decreasing age at menarche, and common risk factors have led investigators to hypothesize potential associations of age at menarche or menstrual characteristics with incidence of adult onset asthma. We evaluated these associations among reproductive age women.
Methods: Study participants were selected from among women enrolled in a pregnancy cohort study. Information on age at menarche, menstrual characteristics, and history of asthma was collected using interviewer-administered questionnaires. Adult onset asthma was defined as asthma first diagnosed after onset of menarche. Women who had no information on asthma and menstrual history and those who were diagnosed with asthma before menarche were excluded. A total of 3,461 women comprised the analytic population. Logistic regression was used to estimate adjusted relative risk (aRR) and 95% confidence intervals (95% CI) relating age at menarche and menstrual characteristics with adult onset asthma.
Results: Mean age at menarche was 12.8 years (standard deviation=1.46). Among study participants, 7.5% were diagnosed with asthma after the onset of menarche. After controlling for potential confounders (age, race, body mass index, and socio-economic status), women who had early menarche (<12 years old) had 60% higher risk of being diagnosed with adult onset asthma as compared with women who did not have early menarche (≥ 12 years old) (aRR= 1.59, 95% CI 1.19 - 2.13). Menstrual irregularities or abnormal (short or long) cycle length were not associated with risk of adult onset asthma. In addition, no significant interaction was observed between age at menarche or menstrual characteristics with body mass index or physical activity (in adolescence) in relation to adult onset asthma.
Conclusion: Early menarche is associated with a higher risk of developing adult onset asthma among reproductive age women. Mechanisms for this association are potential areas of future research.
Keratoconus is the most common ectatic disorder of the corneal. Genetic and environmental factors may contribute to its pathogenesis. The focus of this article is to summarize current research into the complex genetics of keratoconus. We discuss the evidence of genetic etiology including family-based linkage studies, twin studies, genetic mutations, and genome-wide association studies. The genes implicated potentially include VSX1, miR-184, DOCK9, SOD1, RAB3GAP1, and HGF. Besides the coding mutations, we also highlight the potential contribution of DNA copy number variants in the pathogenesis of keratoconus. Finally, we present future directions for genetic research in the understanding of the complex genetics of keratoconus and its clinical significance. As new functional, candidate genes for keratoconus are being discovered at a rapid pace, the molecular genetic mechanisms underlying keratoconus pathogenesis will advance our understanding of keratoconus and promote the development of a novel therapy.
Background: High temperature requirement factor A 1 (HtrA1) and a disintegrin and metalloproteinase 12 (ADAM12), which play roles in placental implantation and placental growth, have been implicated in the pathogenesis of preeclampsia.
Methods: We investigated relative mRNA expression of both genes in placental tissues from women with preeclampsia (N=18) (average gestational age 36 weeks) and an equal number of women with normotensive pregnancies (average gestational age 39 weeks). Real-time polymerase chain reaction was used to measure mRNA extracted from term placental biopsies. Differential gene expression was evaluated using Student's T-test and fold change analyses.
Results: Statistically significant increases in placental HtRA1 (1.69-fold, p=0.030) and ADAM12 (1.48-fold, p=0.010) mRNA expression were observed among preeclamptic cases as compared with normotensive controls. HtrA1 expression was correlated with maternal age (p-value <0.01) among preeclampsia cases.
Conclusion: Increases in HtRA1 and ADAM12 placental gene expression in placentas from preeclamptic pregnancies are consistent with some earlier reports of altered serum protein concentrations in preeclamptic pregnancies. This adds to the literature suggesting that defects in placentation (e.g. involving trophoblast invasion) are of etiologic importance in preeclampsia.