Comparative genomics of casein genes

Abstract

This research paper addresses the hypothesis that comparative genomics can give a new insight into the functionality of casein genes with respect to the casein micelle. Comparative genomics is a rapidly emerging field in computational biology whereby two or more genomes are compared in order to obtain a global view on genomes as well as assigning previously unknown functions for genes. Casein genes are among the most rapidly evolving mammalian genes, with the gene products mainly grouped into four types (αs1-, αs2-, β- and κ-casein). Functionally, casein genes are central to the casein micelle, the exact structure of which is still a subject of intense debate. Moreover, and adding to this complexity, some mammals lack some of the casein genes, although casein micelles have been observed in their milk. This observation has prompted an investigation into the distribution of casein genes across a host of mammalian species. It was apparent from this study that casein gene sequences are very diverse from each other and we confirmed that many mammalian species lack one or more of the casein genes. The genes encoding β- and κ-caseins are present in most mammals whereas α-casein encoding genes are less represented. This suggests different mechanisms for casein micelle formation in different species as well as the functions that are assigned to each individual casein.

Comparative Genomics, Evolutionary and Gene Regulatory Regions Analysis of Casein Gene Family in Bubalus bubalis

“…In reference to the aligned sequence of the CSN gene, high variation has been reported in all the CSN genes. Even though closely related species represent increased sequence similarity with conserved and non-conserved genomic regions (Madende and Osthoff, 2019). In the present study, sequence analysis of CN protein revealed 10 conserved motifs in buffalo, and cattle using the MEME tool.…”

“…Caseins (αs1, αs2, β, and κ) are the primary components of milk protein content in dairy animals. All the mammalian CSN genes are rapidly evolving genes and are mainly classified into four types including CSN1S1, CSN2, CSN1S2, and CSN3 (Madende and Osthoff, 2019). The results of our molecular phylogenetic analysis of the CSN gene family are in consensus as all the representative species were clustered into four taxa.…”

Genetic Diversity in Casein Gene Cluster in a Dromedary Camel (C. dromedarius) Population from the United Arab Emirates

“…In goats and cattle, these genes are mapped on chromosome 6 and span about 250 kb [6]. These genes have been characterized at the genomic [7], transcriptomic [8], and proteomic [9] levels. Furthermore, genetic polymorphisms and variants in casein genes have been reported in various animal species [10], including cattle [11][12][13], goats [14], and sheep [15], with goats and cows having the largest genetic variability.…”

Phylogenetic comparative analysis: Chemical and biological features of caseins (alpha-S-1, alpha-S-2, beta- and kappa-) in domestic dairy animals

“…Divergence in casein genes and the presence or absence of one or more genes encoding caseins explain the different biological and chemical functions of the casein micelles ( 45 ). The genes encoding α-caseins are absent in most mammalian species; for example, human milk lacks αs2-casein, and it may be possible that its role in casein micelle formation could be shifted to αs1-casein ( 14 ). In contrast, genes encoding β-and κ-caseins are widely distributed among mammals.…”

“…Comparative genomic analysis can provide new insights into the functionality of casein genes with respect to the caseins. Comparative genomic analysis is a rapidly emerging field in computational biology whereby two or more genomes are compared to obtain a global view of genomes and their deduced proteomes and assign previously unknown functions to genes with respect to their proteins (14). Computational chemical properties can also pave the way to predicting the properties of deduced proteins.…”