Research Projects

Fertility and reproductive optimization under nutritional scarcity is key to adaptation. Protein deprivation is one of the most common types of nutritional limitation known to affect reproduction in animals, including humans. Thus, understanding the biology and ecology of reproductive adaptation to protein deprivation is important and necessary. How animals evolutionarily adapt to chronic shortage of dietary protein is poorly understood, and is an emerging field. The proposed study aims to address this problem in two parts – one on female fertility, and the other on male fertility and competitive ability. The female fertility part will be addressed using a system of experimentally evolved Drosophila melanogaster populations where female reproductive adaptation (ovarian size and function, reproductive schedule, fecundity) has evolved in response to a form of protein deprivation (dietary live-yeast deprivation). The proposed investigation aims to use these populations to further understand the mechanistic basis of such adaptation. To this effect, we intend to investigate germline maintenance, and follicular development – especially looking at nutrient dependence of the processes. Further, we will investigate the role of noncoding RNA especially, microRNAs in the regulation of follicular development – an emerging field by itself. In the second part, we aim to investigate protein dependence of male fertility and competitive ability. Multifaceted nature of male fertility in D. melanogaster will be leveraged to investigate nutritional constraints affecting the production of functional ejaculate. In addition to the sperm traits (length, number, longevity), we will investigate how seminal fluid composition, a key aspect of male fertility, responds to nutritional changes using a proteomics approach. We will also investigate the expression of accessory gland proteins that play vital roles in fertility and sperm competitive ability. The aim is to gain a comprehensive understanding of nutrition dependence of key male fertility related traits connected to Darwinian fitness. Further, we will assess the role of dietary protein dependent plasticity of testes and accessory gland development, and the putative role of the trade-off between somatic maintenance and reproductive investment. This will be one unique study that brings together nutrient dependent adaptation, and fertility research with a solid foundation of organismal level background data, and an overarching aim to address a fairly nontrivial problem, viz. reproductive adaptation under dietary stress.