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Simple Summary: The Arabian horse is probably one of the most historic horse breeds worldwide. It has been selectively bred by the Bedouin tribes in the steppes of Arabia for over 2000 years. Bedouin tribes have created their own classification of strains based on maternal lines. The aim of our study was to investigate genetic differentiation at the level of (i) the current populations (Desert-Bred, Straight Egyptian and Polish Arabians) and (ii) the traditional Bedouin strains. Two hundred and eleven Arabian individuals, representing 12 strains, were sampled. Mitochondrial DNA D-loop analysis showed higher genetic diversity in the Egyptian and Polish Arabian populations than in the Desert-Bred. No genetic markers distinguishing the traditional strains were highlighted in this study, a fact probably due to the lack of interest in this component in modern breeding programs. Some Polish Arabian individuals, who could not be traced back to the Bedouin tribes, appeared to be genetically distinct from the other studied horses, requiring more in-depth study. This research, complemented by future SNP and Y-chromosome analyses, may provide a more accurate evaluation of the relationships between Arabian horse populations′ genetic and traditional classification. Genetic diversity and phylogenetic relationships within the Arabian show horse populations are of particular interest to breeders worldwide. Using the complete mitochondrial DNA D-loop sequence (916 pb), this study aimed (i) to understand the genetic relationship between three populations, the Desert-Bred (DB), a subset of the Kingdom of Saudi Arabia (KSA), United Arab Emirates (UAE) and Bahrain (BAH), the Straight Egyptian (EG) and the Polish bloodline (PL), and (ii) to assess the accuracy of the traditional strain classification system based on maternal lines, as stated by the Bedouin culture. To that end, we collected 211 hair samples from stud farms renowned for breeding Arabian show horses from Nejd KSA, Bahrain, Egypt, Qatar, Morocco, UAE, and Poland. The phylogenetic and network analyses of the whole mitochondrial DNA D-loop sequence highlighted a great genetic diversity among the Arabian horse populations, in which about 75% of variance was assigned to populations and 25% to strains. The discriminant analysis of principal components illustrated a relative distinction between those populations. A clear subdivision between traditional strains was found in PL, in contrast to the situation of DB and EG populations. However, several Polish horse individuals could not be traced back to the Bedouin tribes by historical documentation and were shown to differ genetically from other studied Bedouin strains, hence motivating extended investigations. [ABSTRACT FROM AUTHOR]

Simple Summary: The history of the Romanov breed goes back more than a century, with the first mention being made in 1802. This breed has unique qualities, such as a good resistance to harsh environments, high litter size, polyestrousity, early maturation and excellent fur coat qualities. In this work, we highlighted several genetic markers involved in these characteristics. The high ovulation rate of the Romanov breed is probably linked to the polymorphism recorded in two genes located on different chromosomes. The breed's adaptation to the harsh environment of its breeding area in the Russian Federation could be associated to a high level of heterozygosity. In addition, the dilemma of its obscure origin was also addressed by comparison with other Russian breeds of different productive orientations. The Romanov breed was evaluated using immunological and genetic markers. The seven blood group systems were characterized with a greater accuracy than in previous works on sheep in the Russian Federation, and were compared to eight ruminant species. Unlike other breeds, Romanov sheep shows a higher frequency of HBA than HBB alleles. There are 3–4 genotypes at the transferrin locus whereas in other breeds 6–11 genotypes have been found. At the albumin locus, the majority of the identified genotypes were heterozygotes, unlike in the other breeds studied. In the prealbumin locus, the Romanov breed was the only one where all the genotypes were heterozygous. We speculate that polymorphism at two loci (BMP-15 and BMPR1B) could effect on the high ovulation rates of Romanov sheep. Based on different genetic markers, the prevalence of heterozygotes in the Romanov sheep could determine their higher viability. A cluster analysis showed the close proximity of 12 populations of the Romanov breed, as the breeding stock come from the Yaroslavl region. [ABSTRACT FROM AUTHOR]

Simple Summary: Egypt is a carrefour between North African Maghreb countries, East Tropical Africa, Arabian Peninsula, and Near East countries including Turkey. The aim of the present work was to describe the genetic relationships between several domestic sheep populations of these regions. All of the present-day Egyptian breeds are coarse woolen and fat-tailed, but archeologists indicate that this tail form was acquired in the Near East later from populations with a thin tail. To test this idea, we used a phylogenetic-derived program to compare the control region of mtDNA of 37 breeds with fat or thin tails. We showed that most breeds seemed to fit with the archeologist hypothesis, whereas one breed indicates a direct migration of a fat-tailed breed from Turkey. Unexpectedly, one of the breeds from South Egypt was strongly linked to the thin-tailed desert breeds of Sudan, raising the question of the events leading to this situation. (1) Background: It has been recognized that the origin of fat-tailed sheep occurred within coarse wool breeds and that this character was introgressed several times into thin-tailed populations. However, no study has investigated this idea for Egyptian breeds using mtDNA analyses. (2) Methods: Using new sequences of the control region, we constructed a database of 467 sequences representing 37 breeds including fat- and thin-tailed ones with 80 Egyptian individuals belonging to six local breeds (Barki, Fallahi, Ossimi, Rahmani, Saidi, Sohagi). The phylogenetic tree obtained with the maximum likelihood method was submitted to the Newick Extra program to count the direct and indirect links between the individuals of each breed. (3) Results: Several Egyptian breeds were strongly connected to "primitive" thin-tailed breeds from Europe, indicating a clear genetic background of the "thin tail" breed type that supports the view of archeologists. In several cases, we suspected Western Asian breeds to be involved in the introgression of the fat tail character. In contrast, the Ossimi breed showed a high affinity to a fat-tailed breed of Western Asia, suggesting a direct migration and no thin tail ancestors. The Saidi is unique as our analyses revealed its strong connection with thin-tailed Sudanese breeds. [ABSTRACT FROM AUTHOR]

(1) Background. Merino is a worldwide sheep breed well known for the quality and quantity of its wool. If there is no doubt that it originates from the Mediterranean Basin and that human selection took place in southern Spain, the populations that potentially contributed to the building of this breed are a matter of debate. Here, we tested whether a Moroccan breed settled on the North Atlantic coast, the Beni Ahsen, could be a good candidate, given the thickness and distribution of fleece covering the head and legs. (2). Methods. Using the control region of the mtDNA, 20 Beni Ahsen sequences were considered in a dataset of 643, including Mediterranean Merino and non-Merino breeds. Unfortunately, the Beni Ahsen is an endangered breed because of a lack of interest from the breeders. (3) Results. European Merino-derived breeds are divided into an Iberian and an Italian cluster, more linked to non-Merino breeds of the same country than between Merino themselves. Beni Ahsen breed is strongly linked to the other Moroccan breeds but shows the greatest number of connections with Merino-derived breeds, especially from Iberia. Interestingly, several other Moroccan breeds are also connected to Iberian Merino. [ABSTRACT FROM AUTHOR]

We identified and analyzed α2,8-sialyltransferases sequences among 71 ray-finned fish species to provide the first comprehensive view of the Teleost ST8Sia repertoire. This repertoire expanded over the course of Vertebrate evolution and was primarily shaped by the whole genome events R1 and R2, but not by the Teleost-specific R3.We showed that duplicated st8sia genes like st8sia7, st8sia8, and st8sia9 have disappeared from Tetrapods, whereas their orthologues were maintained in Teleosts. Furthermore, several fish species specific genome duplications account for the presence of multiple poly-α2,8-sialyltransferases in the Salmonidae (ST8Sia II-r1 and ST8Sia II-r2) and in Cyprinus carpio (ST8Sia IV-r1 and ST8Sia IV-r2). Paralogy and synteny analyses provided more relevant and solid information that enabled us to reconstruct the evolutionary history of st8sia genes in fish genomes. Our data also indicated that, while the mammalian ST8Sia family is comprised of six subfamilies forming di-, oligo-, or polymers of α2,8-linked sialic acids, the fish ST8Sia family, amounting to a total of 10 genes in fish, appears to be much more diverse and shows a patchy distribution among fish species. A focus on Salmonidae showed that (i) the two copies of st8sia2 genes have overall contrasted tissue-specific expressions, with noticeable changes when compared with human co-orthologue, and that (ii) st8sia4 is weakly expressed. Multiple sequence alignments enabled us to detect changes in the conserved polysialyltransferase domain (PSTD) of the fish sequences that could account for variable enzymatic activities. These data provide the bases for further functional studies using recombinant enzymes. [ABSTRACT FROM AUTHOR]

Cell surface of eukaryotic cells is covered with a wide variety of sialylated molecules involved in diverse biological processes and taking part in cell- cell interactions. Although the physiological relevance of these sialylated glycoconjugates in vertebrates begins to be deciphered, the origin and evolution of the genetic machinery implicated in their biosynthetic pathway are poorly understood. Among the variety of actors involved in the sialylation machinery, sialyltransferases are key enzymes for the biosynthesis of sialylated molecules. This review focus on β-galactoside α2,3/6-sialyltransferases belonging to the ST3Gal and ST6Gal families. We propose here an outline of the evolutionary history of these two major ST families. Comparative genomics, molecular phylogeny and structural bioinformatics provided insights into the functional innovations in sialic acid metabolism and enabled to explore how ST-gene function evolved in vertebrates. [ABSTRACT FROM AUTHOR]

The mammalian mono-α2,8-sialyltransferase ST8Sia VI has been shown to catalyze the transfer of a unique sialic acid residues onto core 1 O-glycans leading to the formation of di-sialylated O-glycosylproteins and to a lesser extent to diSia motifs onto glycolipids like GD1a. Previous studies also reported the identification of an orthologue of the ST8SIA6 gene in the zebrafish genome. Trying to get insights into the biosynthesis and function of the oligo-sialylated glycoproteins during zebrafish development, we cloned and studied this fish α2,8-sialyltransferase homologue. In situ hybridization experiments demonstrate that expression of this gene is always detectable during zebrafish development both in the central nervous system and in non-neuronal tissues. Intriguingly, using biochemical approaches and the newly developed in vitro MicroPlate Sialyltransferase Assay (MPSA), we found that the zebrafish recombinant enzyme does not synthetize diSia motifs on glycoproteins or glycolipids as the human homologue does. Using comparative genomics and molecular phylogeny approaches, we show in this work that the human ST8Sia VI orthologue has disappeared in the ray-finned fish and that the homologue described in fish correspond to a new subfamily of α2,8-sialyltransferase named ST8Sia VIII that was not maintained in Chondrichtyes and Sarcopterygii. [ABSTRACT FROM AUTHOR]

We identified and analyzed α2,8-sialyltransferases sequences among 71 ray-finned fish species to provide the first comprehensive view of the Teleost ST8Sia repertoire. This repertoire expanded over the course of Vertebrate evolution and was primarily shaped by the whole genome events R1 and R2, but not by the Teleost-specific R3. We showed that duplicated st8sia genes like st8sia7 , st8sia8 , and st8sia9 have disappeared from Tetrapods, whereas their orthologues were maintained in Teleosts. Furthermore, several fish species specific genome duplications account for the presence of multiple poly-α2,8-sialyltransferases in the Salmonidae (ST8Sia II-r1 and ST8Sia II-r2) and in Cyprinus carpio (ST8Sia IV-r1 and ST8Sia IV-r2). Paralogy and synteny analyses provided more relevant and solid information that enabled us to reconstruct the evolutionary history of st8sia genes in fish genomes. Our data also indicated that, while the mammalian ST8Sia family is comprised of six subfamilies forming di-, oligo-, or polymers of α2,8-linked sialic acids, the fish ST8Sia family, amounting to a total of 10 genes in fish, appears to be much more diverse and shows a patchy distribution among fish species. A focus on Salmonidae showed that (i) the two copies of st8sia2 genes have overall contrasted tissue-specific expressions, with noticeable changes when compared with human co-orthologue, and that (ii) st8sia4 is weakly expressed. Multiple sequence alignments enabled us to detect changes in the conserved polysialyltransferase domain (PSTD) of the fish sequences that could account for variable enzymatic activities. These data provide the bases for further functional studies using recombinant enzymes., Competing Interests: The authors declare no conflict of interest.