The Complexity of the Ovine and Caprine Keratin-Associated Protein Genes.

Sheep (Ovis aries) and goats (Capra hircus) have, for more than a millennia, been a source of fibres for human use, be it for use in clothing and furnishings, for insulation, for decorative and ceremonial purposes, or for combinations thereof. While use of these natural fibres has in some respects been superseded by the use of synthetic and plant-based fibres, increased accounting for the carbon and water footprint of these fibres is creating a re-emergence of interest in fibres derived from sheep and goats. The keratin-associated proteins (KAPs) are structural components of wool and hair fibres, where they form a matrix that cross-links with the keratin intermediate filaments (KIFs), the other main structural component of the fibres. Since the first report of a complete KAP protein sequence in the late 1960s, considerable effort has been made to identify the KAP proteins and their genes in mammals, and to ascertain how these genes and proteins control fibre growth and characteristics. This effort is ongoing, with more and more being understood about the structure and function of the genes. This review consolidates that knowledge and suggests future directions for research to further our understanding.

A study of the phosphorylation proteomic skin characteristics of Tan sheep during the newborn and er-mao stages.

In this experiment, in order to study the formation mechanism of the lamb fur of Tan sheep, skin samples were collected from Tan sheep at the newborn and er-mao stages. Then, the phosphorylated proteomes of the skin samples of Tan sheep at the two different stages were compared and analyzed using a TMT labeled quantitative phosphorylation proteomic technique. A total of 2806 phosphorylated proteins were identified, including 8184 phosphorylation sites. The results of this study's quantitative analysis showed that when compared with the skin samples at the er-mao stage, the phosphorylation levels of 171 sites had been upregulated in the skin samples at newborn stage. Meanwhile, 125 sites had been downregulated at the same stage. As shown by the results of the functional enrichment analysis of the differentially phosphorylated proteins, they had been mainly enriched in the cysteine and methionine metabolism. In addition, the phosphorylation levels of KAP4.7 and KAP13.1 had also varied during the different skin stages. These results indicated that the cysteine metabolism pathways, as well as the phosphorylation modifications of the keratin associated proteins in the skin, played important roles in the formation of the er-mao stage fur of the Tan sheep. Therefore, the findings of this study provided a new angle for interpreting the formation mechanism of er-mao stage fur properties.

Proteomic analysis of the follicular fluid of Tianzhu white yak during diestrus.

The aim of this study was to identify differentially expressed proteins in the follicular fluid of Tianzhu white yak during diestrus. Follicles obtained from female yak were divided into four groups according to their diameter: 0-2, 2-4, 4-6 mm, and greater than 6 mm. The follicular fluid was directly aspirated from the follicles and mixed according to follicular size, and two-dimensional gel electrophoresis was carried out on the crude follicular fluid samples. Thirty-four differentially expressed spots were generated from these four sizes of follicles. Fourteen of these spots were analyzed by MALDI-TOF/TOF-MS and identified as: AS3MT, VDP, ANKRD6, C10orf107 protein, MRP4, MAPKAP1, AGO3, profilin-ß-actin, SPT2 homolog, AGP, AR, RNF20, obscurin-like-1, and one unnamed protein. These proteins were first reported in follicular fluid, in addition to VDP and AGP. Based on existing knowledge of their function and patterns of expression, we hypothesize that most of these differentially expressed proteins play a role in ovarian follicular growth and development, dominant follicle selection, or follicular atresia and development of oocytes; however, the function of the other differentially expressed proteins in reproduction remains ambiguous.

Molecular Characterization of Tick-borne Pathogens in Bactrian Camels and Ticks from Gansu Province, China.

PURPOSE: Ticks are dangerous ectoparasites for humans and other animals, and tick-borne pathogens of Bactrian camels have been epidemiologically surveyed in Gansu Province, China. We aimed to determine the current distribution of tick-borne pathogens among Bactrian camels in Gansu during August 2013 using molecular tools. METHODS: All ticks underwent morphological identification. We extracted DNA from the blood samples and ticks, screened them for Theileria, Babesia, Anaplasma, and Ehrlichia using standard or nested PCR with specific primers. RESULTS: All ticks collected from the skin were identified as Hyalomma asiaticum. The blood and tick samples harbored similar pathogens, including the Theileria species, T. annulata, T. luwenshuni, T. uilenbergi, and T. capreoli, the Anaplasma species A. bovis and uncultured Anaplasma, the Ehrlichia species E. canis and uncultured Ehrlichia, and a new haplotype of Babesia species. CONCLUSION: Our findings of anaplasmataceae and piroplasmida in Bactrian camels in Gansu provide a theoretical basis for deeper investigation into the epidemiology of tick-borne pathogens in these camels.

Plasma Metabolomic Analysis Reveals the Relationship between Immune Function and Metabolic Changes in Holstein Peripartum Dairy Cows.

Dairy cows undergo dynamic physiological changes from late gestation to early lactation, including metabolic changes and immune dysfunction. The aim of this study was to investigate the relationship between immune function and metabolic changes in peripartum dairy cows. Fifteen healthy Holstein dairy cows were enrolled 14 days prior to parturition, and plasma was collected on day −7, 0, 7, and 21 relative to calving. Plasma non-esterified fatty acids (NEFAs), glucose, ß-hydroxybutyric acid (BHBA), immunoglobulin G (IgG), tumor necrosis factor alpha (TNF-α), and interleukin-2 levels were measured, and metabolic profiles were determined using ultra-high-performance liquid chromatography−quadrupole time-of-flight mass spectrometry. The data were analyzed using Tukey−Kramer adjustment for multiple comparisons, and multivariate and univariate statistical analyses were performed to screen for differential metabolites. The results showed that the concentrations of NEFAs, glucose, BHBA, and TNF-α in the plasma significantly increased and concentrations of IgG and interleukin-2 in plasma significantly decreased from −7 d to the calving day (p < 0.05). Additionally, the concentrations of glucose, IgG, and TNF-α significantly decreased from 0 to +7 d, and concentrations of NEFAs decreased significantly from +7 to +21 d (p < 0.05). The following six primary metabolic pathways were identified in all time point comparisons, and L-glutamate, linoleic acid, taurine, and L-tryptophan were involved in these major metabolic pathways. Correlation and pathway analyses indicated that a negative energy balance during the transition period adversely affects immune responses in cows, and L-tryptophan exerts immunomodulatory effects through the Trp-Kyn pathway, resulting in depletion of Trp and elevation of Kyn.

Untargeted Metabolomics Reveals Metabolic Stress Alleviation by Prepartum Exercise in Transition Dairy Cows.

Prepartum exercise (PA) has been proposed as a strategy for the peripartum management of dairy cows; however, the mechanism by which PA affects metabolism has not been elucidated. Here, we investigated the metabolic changes in transition dairy cows with PA. Holstein transition multiparous dairy cows were assigned to an exercise (n = 12) or a control (n = 12) group; the cows in the exercise group walked for a targeted 45 min at 3.25 km/h, two times a day. Plasma non-esterified fatty acid (NEFA), ß-hydroxybutyric acid (BHBA), glucose, and triglyceride levels were measured, and metabolic profiles were analyzed using untargeted mass spectrometry. Compared with those in the control group, the concentrations of NEFA at -7 d, glucose at 0 d, and BHBA at +7 d relative to calving were considerably decreased in the exercise group. Untargeted metabolomics analysis revealed differences in the levels of key metabolites, including kynurenine, tryptophan, homovanillic acid, dopamine, cis-9-palmitoleic acid, and palmitic acid, between the exercise and control group cows. This study suggests that PA may decrease homovanillic acid and cis-9-palmitoleic acid levels and increase tryptophan levels to alleviate the metabolic stress in dairy cows during calving, thereby improving postpartum health.

Differentially phosphorylated proteins in the crimped and straight wool of Chinese Tan sheep.

Proteins can be post-translationally modified and this can be important in the regulation of cellular processes and function. However, little is known about whether protein phosphorylation plays a role in regulating wool fibre properties. In this study, we used a chemical labelling method combined with a high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis to compare the phosphopeptides present in the wool of three Tan sheep with highly crimped wool and three Tan sheep with straighter wool. Thirty-six phosphopeptides that had differences in relative abundance between these two types of wool were identified. These peptides were derived from 28 to 33 different proteins, including two keratins (Ks) and 7 to 12 keratin-associated proteins (KAPs), with these proteins being common structural components of the wool fibre. The crimped wool had a higher relative abundance of phosphorylated K38, K72 and KAP13-x, whereas the straighter wool had a higher relative abundance of phosphorylated KAP2-1, KAP6-1, KAP4-x, KAP10-x and KAP13-y. These results confirm the phosphorylation of wool Ks and KAPs, and suggest that differential phosphorylation of Ks and KAPs may affect wool fibre crimping in Tan sheep. SIGNIFICANCE: Protein phosphorylation can alter the structural conformation and interaction of a protein, and hence affect the cellular processes that the protein undertakes. In this study, we compared the suite of phosphorylated proteins in crimped and straight wool from Chinese Tan sheep and found that some keratins and keratin-associated proteins were phosphorylated. Crimped wool had more keratin phosphorylation, while straight wool had more keratin-associated protein phosphorylation, with this suggesting that wool fibre crimping may be a regulated by phosphorylation of some wool proteins. This suggests that wool traits may be under epigenetic control and that post-translation modifications need to be considered in breeding for different wool types.

Identification of Ovine KRTAP28-1 and Its Association with Wool Fibre Diameter.

Keratin-associated proteins (KAPs) are a diverse group of proteins and form a matrix that cross-links keratin intermediate filaments in hair and wool fibres. From over 100 KAP genes (KRTAPs) identified in mammalian species, KRTAP25-1 is a high sulphur (HS)-KAP gene, which has recently been described in humans. Here, we report the absence of KRTAP25-1 in sheep, and describe a new HS-KRTAP (named KRTAP28-1) in the chromosome region where KRTAP25-1 was expected to be found. Six variants (A-F) of KRTAP28-1 containing eight single nucleotide polymorphisms (SNPs) and a TG repeat polymorphism were detected. One was positioned 30 bp upstream of the transcription start codon and all the others were non-synonymous SNPs, including a nonsense SNP. The TG repeat polymorphism would lead to a reading frame shift at the carboxyl-terminal end. The effect of KRTAP28-1 on wool traits was investigated with 383 Southdown × Merino-cross lambs from seven sire lines. Of the four genotypes with a frequency of over 5%, lambs of genotypes AB and BD produced wool of a smaller MFD than lambs of genotype BC. This shows that KRTAP28-1 is associated with wool fibre diameter, and that variation in this gene might have potential for use as a gene marker for reducing wool fibre diameter.