- A total of 140 Peruvian alpacas of two breeds (Huacaya and Suri) were analyzed for 69 microsatellite markers, in order to make a first approximation to the association analysis with the alpaca fiber diameter, which is the main trait related to alpaca fiber quality. A total of 599 alleles were observed across the two breeds, with a global average of 8.68 alleles per locus. Mean gene diversity in the total population was 0.701, meanwhile both breeds exhibited similar values of 0.686 (Suri) and 0.695 (Huacaya). On the other hand, the values from the inbreeding coefficient (FIS) were 0.154 (Suri) and 0.162 (Huacaya) in both breeds, being the genetic differentiation low between these populations (FST=0.022), and with a gene flow (Nm) value of 9.3. The hierarchical AMOVA corroborated that the differentiation between both breeds only explained the 2.5% of genetic variability. The analysis of association between the microsatellite markers panel and fiber diameter trait was done following an innovative methodology, which was focused in two steps. In the first one, animals were sampled according to a selective genotyping strategy, resulting in six microsatellite markers (LCA68, GLM6, LGU50, VOLP59, LCA85 and LCA90) associated with the genotypes carrying the hypothetical major gene. In the second step, the analysis revealed four significant associations of microsatellite loci (LCA68, VOLP59, LCA9O and GLM6). The subsequent DUNCAN test was used to determine the statistical differences among the fiber diameter EBV means, that corresponded to the different alleles. Eleven out from fourteen alleles of the following loci LCA68 (199, 189, 201, 197, 203 and 205), VOLP59 (112 and110) and LCA90 (243, 229 and 227), showed positive effect (decreasing fiber diameter), and only three alleles for the following loci LCA68 (195) and LCA90 (231 and 249), gave a negative effect (increasing fiber diameter). more »
- Although not the subject of this article, for long term herd health it is important that the following fundamental elements are in place: Good nutrition and husbandry, protection from extremes of weather, parasite control strategies and genetic selection for health (e.g. fertility, adequate milk production, good cria growth rates, freedom from genetic disease, avoidance of excessive in-breeding, etc), not just selection for fleece characteristics and the show ring. more »
- The effect of four enzymes: collagenase, fibrinolysin, hyalurodinase, and trypsin were recorded on the viscosity, motility,percent live spermatozoa and acrosome integrity of Llama and Alpaca semen. Semen samples were collected using a modified artificial vagina for each of the five llamas and five alpacas. A 25% solution of the of enzyme at a concentration of 1 mg/ml was added to the ejaculate. Analysis of variance was used to determine differences in eliminating viscosity and alterations in motility, percent live spermatozoa and the acrosomal integrity at 0 (time of semen collection), 2 and 5 min. In Llama and Alpaca semen, collagenase eliminated viscosity in 100 and 99% of the samples, respectively. Correspondingly, fibrinolysin in 89 and 59%; hyalurodinase in 88 and 36%; and trypsin in 55 and 68% of the samples (p more »
- A component in seminal fluid elicits an ovulatory response and has been discovered in every species examined thus far. The existence of an ovulation-inducing factor (OIF) in seminal plasma has broad implications and evokes questions about identity, tissue sources, mechanism of action, role among species, and clinical relevance in infertility. Most of these questions remain unanswered. The goal of this study was to determine the identity of OIF in support of the hypothesis that it is a single distinct and widely conserved entity. Seminal plasma from llamas and bulls was used as representative of induced and spontaneous ovulators, respectively. A fraction isolated from llama seminal plasma by column chromatography was identified as OIF by eliciting luteinizing hormone (LH) release and ovulation in llamas. MALDI-TOF revealed a molecular mass of 13,221 Da, and 12–23 aa sequences of OIF had homology with human, porcine, bovine, and murine sequences of β nerve growth factor (β-NGF). X-ray diffraction data were used to solve the full sequence and structure of OIF as β-NGF. Neurite development and up-regulation of trkA in phaeochromocytoma (PC12) cells in vitro confirmed NGF-like properties of OIF. Western blot analysis of llama and bull seminal plasma confirmed immunorecognition of OIF using polyclonal mouse anti-NGF, and administration of β-NGF from mouse submandibular glands induced ovulation in llamas. We conclude that OIF in seminal plasma is β-NGF and that it is highly conserved. An endocrine route of action of NGF elucidates a previously unknown pathway for the direct influence of the male on the hypothalamo–pituitary–gonadal axis of the inseminated female. more »
- We aimed to quantify the number, type and arrangement of skin follicles in Huacaya and Suri alpaca skin and correlate their follicle characteristics with fibre traits of harvested fibre and compared these relationships with those of Merino sheep. Fibre and skin samples were collected from the mid-side of 12 Huacaya alpacas, 24 Suri alpacas and 10 Merino sheep. The mean fibre diameter (MFD ± s.e.) of the Huacaya and Suri were: 35.5 ± 0.9 and 28.3 ± 1.0 μm, respectively. The follicle groups found for alpacas were very different from the normal trio of primary follicles found in sheep and goats. The follicle group of the alpacas consisted of a single primary follicle surrounded by a variable number of secondary follicles. The mean ± s.e. primary follicle density was 3.1 ± 0.3 and 2.7 ± 0.1 follicles/mm2 for Huacaya and Suri, respectively. The mean ± s.e. secondary follicle density (SFD) was 13.7 ± 1.2 and 17.5 ± 0.6 follicles/mm2 for Huacaya and Suri, respectively. The mean ± s.e. ratio of secondary to primary follicles (S/P ratio) was 5.1 ± 0.5 for the Huacaya and 7.3 ± 0.2 for the Suri alpacas. The sheep had higher S/P ratios and SFD, lower MFD and produced significantly heavier fleeces. The key correlations found between traits in alpacas include a negative correlation between SFD and MFD (r = –0.71, P = 0.001) and a negative correlation between S/P ratio and MFD (r = –0.44, P = 0.003) and a positive correlation between S/P ratio and total follicle density (r = 0.38, P = 0.010). The study revealed that important relationships exist between alpaca skin follicle characteristics and fibre characteristics. It was the number of secondary follicles in a group that imparts density and a corresponding reduced MFD. more »