Methods for the Study of Gonadal Development

The evolution of epistemological methodologies in anatomy: From antiquity to modern times

Present day scenario regarding epistemological methods in anatomy is in sharp contrast to the situation during ancient period. This study aimed to explore the evolution of epistemological methodologies in anatomy across centuries. In ancient times Egyptian embalmers acquired anatomical knowledge from handling human bodies and likewise anatomical studies in India involved human dissection. Ancient Greeks used theological principles-based methods, animal dissection and human dissection in practice of anatomy. Human dissection was also practiced in ancient China for gaining anatomical knowledge. Prohibition of human dissection led to use of animal dissection in ancient Rome and the trend continued in Europe through Middle Ages. Epistemological methods used by Muslim scholars during Middle Ages are not clearly chronicled. Human dissection returned as primary epistemological method in Renaissance Europe and empirical methods were reinstated after ancient period in human dissection during 16th century. The situation further improved with introduction of pragmatic experiment based approach during 17th century and autopsy-based methods during 18th century. Advances in anatomical knowledge continued with advent of microscope-based methods and emergence of anatomical sections in practice of human dissection in 19th century. Introduction of human observational studies, medical imaging, and molecular methods presented more options in terms of epistemological methods for investigating the human body during 20th century. Onset of 21st century has witnessed dominance of technology-based methods in anatomy. Limited emphasis on ethics in epistemological methodologies since antiquity is a dark aspect of otherwise an eventful evolutionary journey but recent developments are in positive direction.

Comprehensive Transcriptomic Analysis of Mouse Gonadal Development Involving Sexual Differentiation, Meiosis and Gametogenesis

Background

Mammalian gonadal development is crucial for fertility. Sexual differentiation, meiosis and gametogenesis are critical events in the process of gonadal development. Abnormalities in any of these events may cause infertility. However, owing to the complexity of these developmental events, the underlying molecular mechanisms are not fully understood and require further research.

Results

In this study, we employed RNA sequencing to examine transcriptome profiles of murine female and male gonads at crucial stages of these developmental events. By bioinformatics analysis, we identified a group of candidate genes that may participate in sexual differentiation, including Erbb3, Erbb4, and Prkg2. One hundred and two and 134 candidate genes that may be important for female and male gonadal development, respectively, were screened by analyzing the global gene expression patterns of developing female and male gonads. Weighted gene co-expression network analysis was performed on developing female gonads, and we identified a gene co-expression module related to meiosis. By alternative splicing analysis, we found that cassette-type exon and alternative start sites were the main forms of alternative splicing in developing gonads. A considerable portion of differentially expressed and alternatively spliced genes were involved in meiosis.

Conclusion

Taken together, our findings have enriched the gonadal transcriptome database and provided novel candidate genes and avenues to research the molecular mechanisms of sexual differentiation, meiosis, and gametogenesis.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12575-019-0108-y.