Egg-Laying vs Broody Behaviors: Gene Insights in Chickens

Jim Crocker
11th April, 2024

Image Source: Dinesh Madushanka (photographer)

Key Findings

Researchers at Zhejiang University studied the genetic basis of broodiness in Taihe Black-Bone Silky Fowls
They found differences in RNA molecules between broody chickens and high egg-laying chickens
Identifying specific RNA molecules could lead to new ways to manage broodiness in poultry

Understanding the genetic factors that influence broodiness in chickens is crucial for the poultry industry, as broodiness can significantly reduce egg production. Researchers from Zhejiang University have taken a step forward in this field by studying the ovarian transcriptomes, which include both long non-coding RNAs (lncRNAs) and mRNAs, of the Taihe Black-Bone Silky Fowls (TBsf)^[1]. These chickens are particularly known for their pronounced broodiness, making them an ideal subject for investigation. The study focused on comparing the ovarian transcriptomes of broody chickens (BC) and high egg-laying chickens (GC) to identify the genetic differences associated with broodiness. By using RNA sequencing, a method that allows for the detailed analysis of RNA types present in the ovary, the researchers were able to observe the differences in gene expression between the two groups of chickens. Previous studies have shown that hormone-related genes play a significant role in controlling broodiness in birds^[2]. Hormones like progesterone and estradiol, which are involved in reproductive processes, were found to be altered in broody geese. This suggests that similar mechanisms could be at work in the broody Silky chickens. The ovary's function is regulated by a complex interplay of signals, including the secretion of sex steroids and proteins that influence follicular growth and ovulation^[3]. These processes are essential for egg production and are likely disrupted in broody chickens. The study from Zhejiang University builds on this knowledge by exploring the potential involvement of lncRNAs in these regulatory pathways. LncRNAs are a class of RNA molecules that do not encode proteins but are involved in various cellular activities, including the regulation of gene expression^[4]. Their localization within the cell can influence their function, highlighting the importance of understanding their role in the context of ovarian signaling and broodiness. The study also takes into account the dynamic nature of chromatin architecture during folliculogenesis^[5], the process by which ovarian follicles mature. Changes in the organization of chromatin, the material that makes up chromosomes, have been linked to gene expression patterns in granulosa cells, which are critical for follicle development. By integrating these various lines of research, the study from Zhejiang University provides a comprehensive look at the genetic basis of broodiness in Silky chickens. The identification of specific lncRNAs and mRNAs that differ between broody and high egg-laying chickens could lead to new strategies for managing broodiness in poultry. This could include selective breeding programs or the development of interventions that target the genetic pathways identified in the study. In conclusion, the research conducted by Zhejiang University sheds light on the genetic components that contribute to broodiness in chickens, an issue of significant economic importance in the poultry industry. By comparing the ovarian transcriptomes of broody and high egg-laying chickens, the study enhances our understanding of the molecular regulation of broodiness and opens up new avenues for improving egg production.

Genetics Biochem Animal Science