Transcriptomics Study Based On The Sexual Dimorphism Of Hipposideros Pratti

There is a wide range of sexual dimorphism(SD)in the animal world,which refers to the fact that there are other obvious differences between males and females of the same species in addition to reproductive organs,and the corresponding characteristics are often referred to as secondary sexual characteristics.The study of the evolutionary mechanism of sexual dimorphism helps to understand the evolutionary biological issues such as the genetic differentiation and speciation mechanism of natural populations.Traditional studies are usually to carry out long-term field investigations of animals,and then speculate the possible biological significance of related traits.However,due to the characteristics of bats such as flying and nocturnality,the difficulty of traditional studies increased,which has also led to few in-depth studies in the field of bat sexual dimorphism and often limited to the description of the phenomenon itself.The nose-leaves of Hipposideros pratti of the family Hipposideros show obvious sex dimorphism.The fleshy shield of males is significantly larger than that of males,but the specific mechanism leading to this difference is not clear.H.pratti is the research object,using transcriptomics methods to analyze the differences in gene expression levels and genotypes of male bats with different phenotypes,hoping to form the genetic basis and possible underlying evolutionary mechanism of secondary sexual characteristics of H.pratti.A total of 10,652 unigenes were retained by de novo assembly and subsequent de-redundancy filtering.Weighted gene co-expression network analysis(WGCNA)divided the genes into 11 co-expression modules,two of which showed significant correlation with shield size.Enrichment analysis showed that there are multiple functional category in large shield individual group high expression,including the male hormone receptor,DNA damage response and immune cell differentiation and neural activity,learning and memory,detection of mechanical stimulus involved in sensory perception,prompt large shield males in the offensive,frequency of sex,degree of physical fitness and better adaptability to the environment than individual small shield.Since the driving force of the evolution of sexual dimorphism mainly includes ecological factors and sexual selection,considering the difference of organ types,we speculate that the variation of shield morphology is more likely to be the result of sexual selection.In the SNP identification and analysis,a total of 157,327 high-quality SNPs were identified,among which 261 candidate loci related to shield traits were screened.The site is located in the area between gene non-coding regions or more,involved in DNA repair related transcription regulation,the development of the nervous system,regulation of lipid metabolism,regulation of hormone release and so on.Based on the gene expression level of the correlation analysis of enrichment related to access,the variation of gene expression level may be controlled by the individual through the variation of genotype level,which preliminarily revealed the genetic basis of shield morphological variation.In conclusion,at the molecular level,this study provides a possible explanation of the evolutionary mechanism of the secondary sexual characteristics of H.pratti at the molecular level,and provides a reference for future studies of the sexual dimorphism of H.pratti.