The αs2-casein (CN) is a milk protein fraction encoded by the CSN1S2 gene. Previous studies on dromedary milk proteins mainly focused on the other three fractions (αs1-, β- and k-CN), and, although there is globally growing interested in camel milk, studies focusing on αs2-CN are very limited. In this respect, no information has been reported on retrotransposons (RTs). These repeats, also known as Interspersed elements (INEs), are informative genetic markers useful as phylogenetic tools for clustering, evolutionary and population structure studies, rather than for the setup of food traceability methods. Aim of this study was to identify and characterize INEs in the dromedary CSN1S2 gene. Analysis has been carried out using RepeatMasker as bioinformatic tool. Three long interspersed elements (LINEs) were found in introns 1, 10 and 11. The first and the last elements are truncated LINEs 2, respectively 50 bp and 97 bp long. Conversely, the repeat in intron 10 is 149bp long and it is a truncated LINE 1. In addition, three short interspersed elements (SINEs) have been found in introns 8, 9 and 16, with a size of 190bp, 149bp and 207 bp, respectively. The observed six repetitive elements cover 5.6% of the whole dromedary CSN1S2 gene sequence. Camel CSN1S2 gene has more INEs compared with CSN2 gene (five RTs) and they belong to the same types except for the MER5B, which was not found in CSN1S2 gene. Conversely, the CSN1S2 has less INEs compared with CSN3 (7 RTs) and is distinguished by the presence of LINE 2 type, which was not found in camels CSN3. Camel CSN1S2 also shows less INEs than the homologous bovine gene (8 RTs, 5 of them are SINEs and 3 are LINEs). These results agree with previous studies on CSN2 and CSN3 genes and confirm that camel casein genes have lower repetitive elements than cattle. This characteristic is an indication that Tylopoda diverged from Ruminantia before additional retrotransposition events took place at different times during the divergence.
Interspersed repeated elements analysis in Camelus dromedarius CSN1S2 gene / Mohammed, A. A. S.; Versace, C.; Gallo, D.; Gaspa, G.; Cosenza, G.; Pauciullo, A.. - 20:supplement 1(2021), pp. 150-151. (Intervento presentato al convegno ASPA 24nd Congress of the Animal Science and Production Association tenutosi a Padova (Italy) nel September 21-24) [10.1080/1828051X.2021.1968170].
Interspersed repeated elements analysis in Camelus dromedarius CSN1S2 gene.
GALLO D.;COSENZA G.;
2021
Abstract
The αs2-casein (CN) is a milk protein fraction encoded by the CSN1S2 gene. Previous studies on dromedary milk proteins mainly focused on the other three fractions (αs1-, β- and k-CN), and, although there is globally growing interested in camel milk, studies focusing on αs2-CN are very limited. In this respect, no information has been reported on retrotransposons (RTs). These repeats, also known as Interspersed elements (INEs), are informative genetic markers useful as phylogenetic tools for clustering, evolutionary and population structure studies, rather than for the setup of food traceability methods. Aim of this study was to identify and characterize INEs in the dromedary CSN1S2 gene. Analysis has been carried out using RepeatMasker as bioinformatic tool. Three long interspersed elements (LINEs) were found in introns 1, 10 and 11. The first and the last elements are truncated LINEs 2, respectively 50 bp and 97 bp long. Conversely, the repeat in intron 10 is 149bp long and it is a truncated LINE 1. In addition, three short interspersed elements (SINEs) have been found in introns 8, 9 and 16, with a size of 190bp, 149bp and 207 bp, respectively. The observed six repetitive elements cover 5.6% of the whole dromedary CSN1S2 gene sequence. Camel CSN1S2 gene has more INEs compared with CSN2 gene (five RTs) and they belong to the same types except for the MER5B, which was not found in CSN1S2 gene. Conversely, the CSN1S2 has less INEs compared with CSN3 (7 RTs) and is distinguished by the presence of LINE 2 type, which was not found in camels CSN3. Camel CSN1S2 also shows less INEs than the homologous bovine gene (8 RTs, 5 of them are SINEs and 3 are LINEs). These results agree with previous studies on CSN2 and CSN3 genes and confirm that camel casein genes have lower repetitive elements than cattle. This characteristic is an indication that Tylopoda diverged from Ruminantia before additional retrotransposition events took place at different times during the divergence.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
