Differences in serum protein 2D gel electrophoresis patterns of Przewalski's (Mongolian wild horse) and thoroughbred horses

Analysis of genetic diversity and structure of Mongolian horse using microsatellite markers

Mongolian horses are one of the oldest horse breeds, and are very important livestock in Mongolia as they are used in various fields such as transportation, food (milk, meat), and horse racing. In addition, research and preservation on pure Mongolian breeds are being promoted under the implementation of the new Genetics of Livestock Resources' act in Mongolia. However, despite the implementation of this act, genetic research on Mongolian horses using microsatellites (MS) has not progressed enough. Therefore, this study was conducted to analyze the genetic polymorphism of five breeds (Gobi shankh, Tes, Gal shar, Darkhad, and Undurshil) using 14 MS markers recommended by International Society for Animal Genetics (ISAG). The mean number of alleles (MNA) was 8.29, expected heterozygosity frequency (H_Exp) was 0.767, observed heterozygosity frequency (H_Obs) was 0.752, and polymorphism information content (PIC) was 0.729. The Nei's genetic distance analysis showed that the genetic distance between Gobi shankh and Darkhad horses was the farthest, and the other three breeds, Tes, Gal shar, and Undurshil were found to be close to each other. Similarly, the principal coordinate analysis (PCoA) and factorial correspondence analysis (FCA) showed that the Gobi shankh and Darkhad horses were genetically distinct from other breeds. On the other hand, it appears that Tes, Gal shar, and Undurshil horses, which are genetically similar, most likely interbred with each other. Therefore, it is expected that these results will help the conservation of genetic resources in Mongolia and the establishment of policies related to Mongolian horses.

Quantitative analysis of the serum proteome during early pregnancy in mares

Equine pregnancy is currently diagnosed by rectal palpation, ultrasonographic examination, or by measuring changes in hormones in the blood. In the present study, we identified proteins that are differentially expressed in the sera of early pregnant and non-pregnant mares in order to develop a novel method for diagnosing equine pregnancy. Serum samples were obtained from 18 adult mares, pregnancy at day 32 after ovulation (n = 9) and in diestrus (n = 9). Proteomic analysis of the samples was conducted using liquid chromatography-electrospray ionization-tandem mass spectrometry. We identified 467 proteins from a total of 3514 peptides. Thirty-two proteins (15 upregulated and 17 downregulated) were significantly differentially expressed between the two groups. The Gene Ontology enrichment analysis revealed that they are related to extracellular matrix assembly, blood coagulation, and hemostasis, and the prominent molecular functions were integrin binding, cell adhesion molecule binding, and glycine C-acetyltransferase activity. The pathway analysis of Kyoto Encyclopaedia of Genes and Genomes showed that the top three pathways identified were glycine, serine, and threonine metabolism; cysteine and methionine metabolism; and ether lipid metabolism. The selected five serum proteins were newly potential candidates for pregnancy diagnosis in mares.

Label-Free Mass Spectrometry-Based Quantitative Proteomics Analysis of Serum Proteins During Early Pregnancy in Jennies (Equus asinus)

Early pregnancy in jennies is routinely determined by palpation per rectum or ultrasonography and also by detecting steroid hormone and chorionic gonadotropin levels in the blood, plasma, and serum. Herein we applied label-free mass spectrometry-based quantitative proteomics to identify serum proteins that were differentially expressed between early pregnant (day 45 after ovulation) and non-pregnant jennies. Bioinformatics analysis allowed illustration of pathways potentially involved in early pregnancy. We identified 295 proteins from a total of 2,569 peptides. Twenty-five proteins (22 upregulated and three downregulated) were significantly differentially expressed between the early pregnant and non-pregnant groups. The majority of the differentially expressed proteins were involved in defense response, early embryonic development, and hormone signaling pathways. Furthermore, functional protein analyses suggested that proteins were involved in binding, enzyme inhibitor activity, and enzyme regulator activity. Five serum proteins—granulin precursor/acrogranin, transgelin-2, fibronectin, fibrinogen-like 1, and thrombospondin 1—can be considered as novel, reliable candidates to detect pregnancy in jennies. To the best of our knowledge, this is the first study to use label-free mass spectrometry-based quantitative proteomics to analyze serum proteins during early pregnancy in jennies. Our results should facilitate the identification of valuable pregnancy diagnostic markers in early pregnant jennies.

Characterizing the Serum Proteome of Donkeys (Equus asinus)

Serum and plasma are commonly used in clinical practice considering the widely accepted fact that the "normal" protein expression pattern of a healthy animal changes under disease conditions. We herein used a label-free mass spectrometry-based quantitative proteomics approach to characterize the serum proteome of donkeys. A total of 277 unique proteins were identified from 2,388 unique peptides. Gene ontology analyses showed that the most frequent processes were related to metabolic activities and biological regulation, response to stimulus, and immune system processes. The main annotated areas of origin were the extracellular region, extracellular region part, and organelle, and their molecular functions included binding, catalytic activity, and molecular function regulator. Analyses using the Clusters of Orthologous Groups for Eukaryotic Complete Genomes database indicated that the identified proteins could be categorized into three main groups: signal transduction mechanisms, amino acid transport and metabolism, and defense mechanisms. Most of the unique proteins were associated with the complement and coagulation cascades, and they participated in several disease-related metabolic pathways. Our results should be crucial for further analyses of changes in different physiological and pathophysiological conditions in donkeys.

ACUTE PHASE PROTEINS AS A MARKER OF RESPIRATORY INFLAMMATION IN PRZEWALSKI'S HORSE (EQUUS FERUS PRZEWALSKII)

Acute phase proteins are sensitive markers of inflammation, which are highly conserved across taxa. Although the utility of these proteins are becoming well defined in human and domestic animal medical fields, their role in nondomestic species remains unclear. In this communication, a 20-yr-old Przewalski's horse was presented for unresolving aspiration pneumonia, which cultured a unique Actinomyces-like bacteria. Despite waxing and waning clinical signs and minimal changes on baseline hematologic analysis, protein electrophoresis, serum amyloid A, and surfactant protein D serum concentrations showed changes that more accurately reflected the clinical severity of this case.