Mongolia White Cashmere Goats Research Articles

A novel missense (A79V) mutation of goat PROP1 gene and its association with production traits

As a paired class homeodomain transcription factor, mutations of PROP1 (Prophet of POU1F1) are responsible for deficiencies of GH, PRL, TSH, LH and FSH. Regarding mutations of GH, PRL, and POU1F1 genes significantly associating with different production traits, PROP1 gene is a novel important candidate gene for detecting genetic variation and association analysis in marked-assist selection (MAS) program. Therefore, the objective of this study is to detect goat PROP1 gene mutation and its association with production traits. Herein, a novel mutation (AF453512:g.1795C>T) within PROP1 gene is revealed by PCR-SSCP and DNA sequencing methods, and genotyped by Hin6I PCR-RFLP method in 1,344 individuals belonging to eight goat breeds. Only two genotypes (CC and CT) are revealed and the frequencies of allele C go from 0.9014 to 1.000 in analyzed populations. The genetic diversity analysis reveals that all PIC values are less than 0.1619, implying that the Hin6I locus within PROP1 gene possesses low genetic diversity in goat. Furthermore, nucleotide sequence analysis shows that AF453512:g.1795C>T results in a missense amino acid (A79V). But, association analysis demonstrates no significant differences between different genotypes and production traits (such as body weight, cashmere yield, fiber length and wool thickness) of Inner Mongolia White Cashmere goat (P > 0.05), as well as no significant relationship between different genotypes and average milk yield (P > 0.05). Although Hin6I polymorphism can not be used as a molecular marker for production traits in MAS, the present work presents preliminary novel missense mutation which extends the spectrum of genetic variations of goat PROP1 gene and may benefit for considering its association with other biophysical and biochemical indexes.

The polymorphism of a novel 30 bp-deletion mutation at KAP9.2 locus in the cashmere goat

The keratins and keratin-associated proteins (KAPs) are a large heterogeneous group of proteins that make up about 90% of the cashmere fiber. Keratin-associated proteins 9.2 gene ( KAP9.2) is one of the ultra high sulfur KAPs, which might play an important role in the bundling of intermediate filaments. In this study, the deletion/insertion mutation of KAP9.2 gene in 997 cashmere goat samples was firstly detected, at the same time, parts of these samples were sequenced. The results showed that two alleles were detected at this KAP9.2P1 locus, named allele W and D. The frequencies of the KAP9.2-W allele in Inner Mongolia White cashmere ( n = 785) and Shaanbei White cashmere goat breeds ( n = 212) were 0.878 and 0.790, respectively. The χ 2-test showed that the genotype distributions in these two cashmere goat breeds were not in agreement with Hardy–Weinberg equilibrium. According to the classification of polymorphism information content (PIC), Shaanbei White cashmere goat was more polymorphic at this locus. Moreover a 30 bp-deletion mutation was described at KAP9.2P2 locus for the first time and no deletion/insertion was described at KAP9.2P1 locus. The results possibly revealed that the size polymorphism existed in the two Chinese cashmere goat and the 30 bp-deletion mutation was possibly caused by variations in the number of the decapeptide repeat structures.

A PstI polymorphism at 3′UTR of goat POU1F1 gene and its effect on cashmere production

POU1F1 is a positive regulator for prolactin (PRL) whose metabolites may directly or indirectly affect some aspects of the hair growth cycle, therefore, POU1F1 gene is an important candidate gene for cashmere traits selection through marker-assisted selection (MAS). Hence, in this study, the PCR-RFLP method was applied to detect a T>C transition determining a PstI polymorphism at the 3'UTR of POU1F1 locus and evaluate its associations with cashmere traits in 847 Inner Mongolia White Cashmere goats. In the analyzed population, the allelic frequencies for the T and C alleles are 0.959 and 0.041, respectively and the genotypic frequencies are in Hardy-Weinberg equilibrium (P > 0.05). Moreover, significant statistical relationships between the PstI polymorphism of POU1F1 gene and goat cashmere yields were found (*P < 0.05). When compared with TC genotype, TT genotype was associated with superior cashmere yields in 2, 4, and 5 years old individuals, as well as with average cashmere yield. Hence, TT genotype is suggested to be a molecular marker for senior cashmere yield.

The PCR-SSCP and DNA sequencing methods detecting a large deletion mutation at KAP6.2 locus in the cashmere goat

It is known that keratin-associated proteins 6.2 gene ( KAP6.2) is an important structural gene responsible for the cashmere. So in this study, the polymorphism of KAP6.2 gene was firstly detected by PCR-SSCP and DNA sequencing methods in 1052 cashmere goat samples. The results showed that two alleles were detected at the locus, which were named as allele O and X. Frequencies of KAP6.2-O allele in Inner Mongolia White cashmere ( n = 847) and Shaanbei White cashmere goat breeds ( n = 205) were 1.000 and 0.856, respectively. Inner Mongolia White cashmere goat was monomorphic at this locus, while Shaanbei White cashmere goat was at low polymorphic level. Therefore, the allele KAP6.2-X was considered as the breed characterization of Shaanbei White cashmere goat at KAP6.2 locus. Further sequencing analysis showed that a 24-bp deletion mutation was described for the first time in Shaanbei, while Inner Mongolia White cashmere goat did not have the deletion. The study indicated that deletion mutation was predicted as a possible cause for the multiple pattern cashmere in Shaanbei White cashmere goat.

Effects of photoperiod and melatonin on nitrogen partitioning and body composition in Inner Mongolia white Cashmere goats

Effects of photoperiod and melatonin on nitrogen partitioning and body composition in Inner Mongolia white Cashmere goats

Effects of photoperiod and melatonin on nitrogen partitioning and production performance of Inner Mongolia White Cashmere Goats

This study investigated the effect of photoperiod and melatonin (MT) on nitrogen partitioning in Inner Mongolia White Cashmere goats in telogen in order to regulate nitrogen partitioning between the body and the fur, and promote cashmere production. Thirty-six castrated mature goats, with live weights ranging from 23 to 25 kg, were randomly allocated into three groups then exposed to different photoperiods (long daily photoperiod, LDPP; short daily photoperiod, SDPP; natural daily photoperiod, NDPP). In each group, half of the goats were implanted with MT. Total nitrogen sediment (ΔN) was tested with a general digestive and metabolism method. Body nitrogen sediment (NB) was measured by isotope dilution technique of tritiated water at the beginning and at the end of the experiment (NB = BNend − BNbeg) and fur nitrogen deposited (NF) was calculated using the formula NF = ΔN − NB. Results showed that: (1) there was a significant difference in NB and NF partitioning in different treatments of photoperiod and MT. The NF partitioning was increased with the shortening of photoperiod and it was higher in the implanted groups than in the non-implanted groups. The minimum and maximum percentages in LDPP and SDPP + MT were (23.6 ± 0.46)% and (36.1 ± 0.79)% respectively. There was a strong interaction between SDPP and implantation of MT; while BN partitioning showed the reverse for photoperiod and implantation of MT; (2) there is an additional cashmere production of (338.83 ± 72) g in SDPP and implanted groups with an average increase of 73.86%. The traits of the newly grown cashmere were all in the range of the textile standard; (3) hormones related to nitrogen partitioning and body composition varied with different treatments: the levels of MT and insulin (INS) increased with the shortening of photoperiod and were higher in the implanted groups than in the non-implanted groups, and there was a strong interaction between SDPP and MT implantation; prolactin, insulin like growth factor 1 and leptin showed the opposite results to MT and INS. This study provides evidence that MT and photoperiod can be used to regulate nitrogen partitioning, modulate cashmere goat body composition and improve cashmere production in practice. The technique can be extended to Inner Mongolia and other cashmere goat raising areas in China.

Estimates of Genetic Parameters and Genetic Trends for Production Traits of Inner Mongolian White Cashmere Goat

Two different animal models, which differ in whether or not taking maternal genetic effect into account, for estimating genetic parameters of cashmere weight, live body weight, cashmere thickness, staple length, fiber diameter, and fiber length in Inner Mongolia White Cashmere Goat were compared via likelihood ratio test. The results indicate that maternal genetic effect has significant influence on live body weight and cashmere thickness, but no significant influence on the other traits. Using models suitable for each trait, both genetic parameters and trends were analyzed with the MTDFREML program. Heritability estimates from single trait models for cashmere weight, live body weight, cashmere thickness, staple length, fiber diameter and fiber length were found to be 0.30, 0.07, 0.21, 0.29, 0.28 and 0.21, respectively. Genetic correlation estimates from two-trait models between live body weight and all other traits (-0.06~0.07) was negligible, as were those between fiber diameter and all other traits (-0.01~0.03) except cashmere thickness (0.19). Cashmere weight and staple length had moderate to low genetic correlations with other traits (-0.24~0.39 and -0.24~0.34, respectively) except for live body weight and fiber diameter. Cashmere thickness had a strong genetic correlation with fiber length (0.81), and low genetic correlation with other traits (0.19~0.34) except live body weight. Genetic trend analysis suggests that selection for cashmere weight was very effective, which has led to the slow genetic progress of cashmere thickness and fiber length due to their genetic correlations with cashmere weight. The selection for live body weight was not effective, which was consistent with its low inheritability.