Reproductive behavior and health in consanguineous marriages

In many regions of Asia and Africa, consanguineous marriages currently account for approximately 20 to 50% of all unions, and preliminary observations indicate that migrants from these areas continue to contract marriages with close relatives when resident in North America and Western Europe. Consanguinity is associated with increased gross fertility, due at least in part to younger maternal age at first livebirth. Morbidity and mortality also may be elevated, resulting in comparable numbers of surviving offspring in consanguineous and nonconsanguineous families. With advances in medicine and public health, genetic disorders will account for an increased proportion of disease worldwide. Predictably, this burden will fall more heavily on countries and communities in which consanguinity is strongly favored, as the result of the expression of deleterious recessive genes. However, studies conducted in such populations indicate that the adverse effects associated with inbreeding are experienced by a minority of families.

Reproductive queue without overt conflict in the primitively eusocial wasp Ropalidia marginata

Colonies of the primitively eusocial wasp Ropalidia marginata consist of a single egg layer (queen) and a number of non-egg-laying workers. Although the queen is a docile individual, not at the top of the behavioral dominance hierarchy of the colony, she maintains complete reproductive monopoly. If the queen is lost or removed, one and only one of the workers potential queen (PQ)] becomes hyperaggressive and will become the next queen of the colony. The PQ is almost never challenged because she first becomes hyperaggressive and then gradually loses her aggression, develops her ovaries, and starts laying eggs. Although we are unable to identify the PQ when the queen is present, she appears to be a ``cryptic heir designate.'' Here, we show that there is not just one heir designate but a long reproductive queue and that PQs take over the role of egg-laying, successively, without overt conflict, as the queen or previous PQs are removed. The dominance rank of an individual is not a significant predictor of its position in the succession hierarchy. The age of an individual is a significant predictor, but it is not a perfect predictor because PQs often bypass older individuals to become successors. We suggest that such a predesignated reproductive queue that is implemented without overt conflict is adaptive in the tropics, where conspecific usurpers from outside the colony, which can take advantage of the anarchy prevailing in a queenless colony and invade it, are likely to be present throughout the year.

Comparative proteomic analysis of primordial follicles from ovaries of immature and aged rats

Age related decline in reproductive performance in women is well documented and apoptosis has been considered as one of the reasons for the decline of primordial follicle reserve. Recently we observed a decline in the efficiency of DNA repair ability in aged rat primordial follicles as demonstrated by decreased mRNA levels of DNA repair genes BRCA1 and H2AX. In the present study, a two-dimensional electrophoresis (2DE) proteomic approach was employed to identify differentially expressed proteins in primordial follicles isolated from ovaries of immature (approximate to 20 days) and aged (approximate to 400-450 days) rats. Using MALDI-TOF/TOF MS, we identified 13 differentially expressed proteins (p<0.05) which included seven up-regulated and six down-regulated proteins in aged primordial follicles. These proteins are involved in a wide range of biological functions including apoptosis, DNA repair, and the immune system. Interestingly, the differentially expressed proteins such as FIGNL1 (DNA repair) and BOK (apoptotic protein) have not been previously reported in the rat primordial follicles and these proteins can be related to some common features of ovarian aging such as loss of follicle reserve and genome integrity. The quantitative differences of two important proteins BOK and FIGNL1 observed by the proteomic analysis were correlated with the transcript levels, as determined by semi-quantitative RT-PCR. Our results improve the current knowledge about protein factors associated with molecular changes in rat primordial follicles as a function of aging and our understanding of the proteomic processes involved in degenerative changes observed in aging primordial follicles.