Traits Of Economic Importance Research Articles

Endogenous Auxin Content Contributes to Larger Size of Apple Fruit.

Fruit size is an important economic trait that is controlled by multiple genes. However, the regulatory mechanism for fruit size remains poorly understood. A bud sport variety of “Longfeng” (LF) apple (Malus domestica) was identified and named “Grand Longfeng” (GLF). The fruit size of GLF is larger than that of LF, and both varieties are diploid. We found that the cell size in GLF fruit was larger than that of LF. Then, we compared the fruit transcriptomes of the two varieties using RNA-Seq technology. A total of 1166 differentially expressed genes (DEGs) were detected between GLF and LF fruits. The KEGG analysis revealed that the phytohormone pathway was the most enriched, in which most of the DEGs were related to auxin signaling. Moreover, the endogenous auxin levels of GLF fruit were higher than those of LF. The expressions of auxin synthetic genes, including MdTAR1 and MdYUCCA6, were higher in GLF fruit than LF. Collectively, our findings suggest that auxin plays an important role in fruit size development.

Construction of the first high-density genetic map for growth related QTL analysis in Ancherythroculter nigrocauda

Ancherythroculter nigrocauda is a fish endemic to the upper areas of the Changjiang (Yangtze) River in China. Quantitative trait locus (QTL) mapping is a powerful tool to identify potential genes affecting traits of economic importance in domestic animals. In this study, a high-density genetic map was constructed with 5 901 single nucleotide polymorphism (SNP) makers by sequencing 92 individual fish from a F1 family using the specific-locus amplified fragment sequencing approach. Initially, 48 QTLs for total length, body length, body height, and body weight were identified according to the high density of the genetic map with 24 LGs, a total length of 3 839.4 cM, and marker spacing of about 0.82 cM. These QTLs explained 27.1%–49.9% of phenotypic variance. The results of this study suggest that major QTLs are responsible for the growth of A. nigrocauda, and these are potentially useful in comparative genomics research, genome assembly, and marker-assisted breeding programs for this species.

PSIII-6 Comparisons of high-density genomic data in Holsteins differing in coat type

Abstract Preliminary studies have reported that wild type-haired (WT) Holstein cattle have greater productive potential at a genomic level than their slick-haired (SL) counterpart. The objective of the present study was to evaluate, through a panel of commercial genetic markers (Igenity Elite, Neogen Corp), 49 Holsteins descendants SL [32 SL (n = 11 males and 21 females) and 17 WT (n = 2 males and 15 females)] from the Agricultural Experiment Station of Puerto Rico. These animals received a predictive genomic transmission capacity (PTA) based on DNA tests using more than 100,000 bovine genome markers, which contain information from their parents for a more accurate measure of genetic potential. Traits evaluated included measures of productivity, health, type and other indexes such as: net merit, milk yield, somatic cell score, among others. The data was analyzed using Proc GLIMMIX in SAS and the differences between means were determined by the Tukey test. Various subsets of animals were compared; however, no main differences were found between SL and WT (P >0.05), except for stature (-1.07±0.17 vs -0.39±0.26; P = 0.02, respectively). In a second subset, only lactating cows were evaluated (SL n = 7 and WT n = 7) and differences were found for: hypocalcemia (0.03±0.06 vs -0.21±0.06; P = 0.01), mastitis (-0.11±0.24 vs 0.90±0.24; P = 0.01), PTA type (-0.98±0.26 vs -0.11±0.26; P = 0.03), udder composite (-0.96±0.26 vs -0.07±0.26; P = 0.02), stature (-0.91±0.30 vs 0.04±0.30; P = 0.04), dairy form (-1.64±0.26 vs -0.65±0.26; P = 0.02), fore udder attachment (-0.77±0.30 vs 0.41±0.30; P = 0.02), rear udder height (-1.39±0.34 vs -0.18±0.34; P = 0.03) and width (-1.42±0.29 vs -0.17±0.29; P = 0.01), and udder depth (-0.73±0.27 vs 0.82±0.27; P = 0.002), respectively. These results suggest that SL males and females are genomically similar to WT for the most important economic traits when descending from a SL dam and when compared as a single group. However, differences in type and health traits may occur if the females are compared alone.

33 Genetic parameters for reproductive traits in purebred and crossbred swine

Abstract For swine breeding programs, testing and selection programs are located in nucleus units that are generally managed differently and with higher health levels than commercial herds where descendants of nucleus animals are expected to perform. This approach assumes that superior animals selected in nucleus herds will have progeny with superior performance at the commercial level. There is clear evidence that this may not be true for all traits of economic importance and thus methods including data collected at the commercial level may increase accuracy of selection at the nucleus level. This study’s goal was to estimate genetic parameters for five reproductive traits between two purebred maternal nucleus populations and their commercial F1 offspring: Total Number Born, Number Born Alive, Number Born Alive > 1kg, Number Weaned, and Litter Weight. Estimates were based on single-step GBLUP in the BLUPF90 programs by utilizing any two combinations of a purebred and the F1 population, and by using all three populations jointly. The genomic relationship matrix between the three populations was generated by using within-population allele frequencies for relationships within a population, and across-population allele frequencies for relationships of the F1 with the purebred animals. The two purebred populations were assumed to be genetically unrelated. The use of two versus three populations did not impact estimates of heritability, additive variance, or genetic correlations. Heritabilities ranged from 0.02 to 0.09 for the F1, from 0.07 to 0.18 for Landrace, and from 0.07 to 0.21 for Yorkshire. Genetic correlations between the same traits in F1 and Landrace ranged from 0.22 to 0.93, and from 0.31 to 0.84 for F1 and Yorkshire. This range of genetic correlations indicates that the use of crossbred information can aid in the selection of purebreds for commercial crossbred performance for some traits. Funded by Genome Canada Genomic Applications Partnerships Program.

84 Evaluation of hair coat shedding ability as an adaptive trait in Angus cattle in the southern U.S

Abstract The objective of this study was to evaluate winter hair coat shedding ability and the association to cow production performance. This work was a collaborative effort from the S-1064 multi-state research project. Data were collected on spring and fall-calving purebred and commercial Angus females with calves (n = 1192) from March until July from 2008 to 2018 in Mississippi, Arkansas and Texas. Dams were observed once monthly by two trained technicians for winter hair coat shedding and give a visual hair shedding score of 1 to 5 with 1 indicating 100% shed, 2 = 75% shed, 3 = 50% shed, 4 = 25% shed, and 5 indicating 0% shedding of the winter hair coat. Month of first shedding (MFS) was determined once a female reached an average hair shedding score of ≤ 3.5 for any given month. Calf birth and weaning weights were considered as performance of the dam. For cow performance, the response variables included AdjBW and d205wt of the calf. Data were analyzed using the MIXED procedure of SAS with significance declared at P ≤ 0.05. The model included MFS as a fixed effect with calf sex as a covariate and calf sire as a random effect. Females that obtained a shedding score of ≤ 3.5 by May had heavier calves at birth (P ≤ 0.01) when compared with those that shed in June and July, with July weights being the lightest. Females that scored ≤ 3.5 by May has significantly heavier d205wt (P ≤ 0.01) when compared to those that shed by June and July. When comparing locations, females in Arkansas shed later (P ≤ 0.01) when compared with both Mississippi and Texas, which were similar. Shedding ability could be an important economic trait to be considered in cow-calf operations.

Characterizing miRNA and mse-tsRNA in fertile and subfertile yak bull spermatozoa from Arunachal Pradesh

Male fertility in farm animals is considered as an important economic trait. The phenomenon of spermatogenesis plays a dynamic functional role in determining the viability of sperm and thereby can impact on fertility-driven complications. The process of spermatogenesis is controlled by numerous molecular factors and requires a precisely regulated pattern of gene expression. The role of small noncoding RNAs in altering gene expression has been extensively studied. However, limited information is available apropos their role in yak spermatogenesis. The present study aimed to evaluate the assessment of some significant microRNAs and their expression pattern in the body tissues and sperm of fertile and subfertile yak from Arunachal Pradesh besides identified a novel class of sperm enriched small RNA 'mature-sperm-enriched small RNA' (mse-tsRNA) in Yak spermatozoa. The RNAwas extracted from tissue and sperm using 27 gauge needles and subsequently reverse transcribed into small RNA cDNAs. The PCR positive sperm-predominant miRNAs were validated by quantitative reverse transcriptase PCR (qRT-PCR) for their expression in fertile and subfertile yak. Of the 22 microRNAs, the miRNA19a, miRNA142 and miRNA143 showed higher expression in the subfertile yak, whereas expression of miRNA7d, miRNA23a and miRNA23b were found elevated in the fertile animal. The presence of these small noncoding RNAs in yak sperm and testis indicated the legitimate involvement of their role in yak bull fertility.

Factors affecting calving ease in Egyptian buffalo.

Calving ease (CE) is a trait of economic importance that affects animal welfare and farm profitability. The objective of present study was to investigate genetic and environmental factors affecting CE among Primiparous (PP) and multiparous (MP) buffaloes. A total of 9,627 records from 1999 MP and 2,110 PP recorded during the period from 1988 to 2018 were considered. Herd, season of calving, year of calving, birth weight, parity order and gestation length significantly affected CE rate, while age at first calving and sex of calf had no significant effects. Direct and maternal heritabilities of CE in PP and MP were 0.06 and 0.01, respectively. The low heritability of CE indicated that direct selection may not be an effective method to improve CE trait in Egyptian buffalo.

Rabbits - their domestication and molecular genetics of hair coat development and quality.

The European rabbit (Oryctolagus cuniculus) is the only representative of its genus living in present-day Europe and North Africa, and all domestic rabbits are descendants of this one species, which is native to the Iberian Peninsula. There are over 300 breeds of rabbits that differ in size, coat color, length of ears and type of fur. Rabbits are bred for various reasons, such as for laboratory animals and a source of meat, wool and fur, as well as for pets and exhibition animals. The hair coat is a important economic trait of rabbits. Its development and quality are influenced by various factors, both environmental and genetic. The genetic mechanisms underlying its development have not been thoroughly researched. The aim of this review is to discuss the domestication of rabbits and the different aspects of rabbit genetics. A brief review of the properties of rabbit hair coat, hair coat development and hair cycle will be provided, followed by discussion of the factors regulating hair coat development, molecular control of hair coat development and the role of non-coding RNAs in the regulation of gene expression in the hair follicles of rabbits. Information about genetic regulation of pathways could provide useful tools for improving hair coat quality and be of practical use in rabbit breeding.

Analysis of Relative Scent Intensity, Volatile Compounds and Gene Expression in Freesia "Shiny Gold".

Scent is one of the most important economic traits in Freesia hybrida. “Shiny Gold”, a popular cultivar in South Korea, is widely cultivated for its scent. The relative scent intensity of “Shiny Gold” was approximately 16% higher in full-bloomed flower when compared to the yellow bud stage, while tissue-specifically, tepals showed higher intensity in electronic-nose (e-nose) analysis. E-nose analysis also showed that the scent intensity of “Shiny Gold” was higher and lower than “10C3-424” and “10C3-894”, respectively, and was similar to “Yvonne”. These results correlated to those of the olfactory tests. In total, 19 volatile compounds, including linalool, β-ocimene, D-limonene, trans-β-ionone were detected in gas chromatography–mass spectrometry analysis. Among these, linalool was the major volatile compound, accounting for 38.7% in “Shiny Gold”. Linalool synthase and TPS gene expression corresponded to the scent intensity of the four cultivars, with the lowest expression in the “10C3-424”. TPS 2, TPS 3, TPS 5, TPS 6 and TPS 8 were highly expressed in both bud and flower in “Shiny Gold”, while the expression of TPS 4 was lower, relative to other TPS genes in both the flowering stages. These results may aid in enhancing scent composition in Freesia cultivars using marker-assisted selection.

Elite allele mining for growth rate traits in common carp ( Cyprinus carpio ) by association analysis

Growth is one of the important economic traits to be improved in the breeding of common carp, yet the genetic basis in it remains unclear. In this study, a GoldenGate assay containing 1,536 SNP was used to genotype a full-sib panel of 68 individuals of mirror carp Cyprinus carpio. Association studies were carried out between SNP and growth rate for three consecutive months of the panel. 15 loci significantly associated with growth rate were identified using the general linear model and the mixed linear model, which located in eight chromosomes (chr6, 8, 9, 11, 20, 28, 32 and 35) and four scaffolds (scaffold902, 28835, 29008 and 29015). The phenotypic variance of these associated loci ranged from 6.4% to 19.2%. The elite alleles were mined based on the average phenotypic allele effect (AAE) of each allele. 15 elite alleles were screened out with 6.60% higher than the average phenotypic allele and 16.88% higher than the non-elite ones among the four traits. Meanwhile, 15 candidate genes were scanned and annotated. The loci and elite alleles of growth rate identified may facilitate marker-based breeding for rapid growth in common carp.

Genetic parameters for methane emission traits in Australian dairy cows

Methane is a greenhouse gas of high interest to the dairy industry, with 57% of Australia's dairy emissions attributed to enteric methane. Enteric methane emissions also constitute a loss of approximately 6.5% of ingested energy. Genetic selection offers a unique mitigation strategy to decrease the methane emissions of dairy cattle, while simultaneously improving their energy efficiency. Breeding objectives should focus on improving the overall sustainability of dairy cattle by reducing methane emissions without negatively affecting important economic traits. Common definitions for methane production, methane yield, and methane intensity are widely accepted, but there is not yet consensus for the most appropriate method to calculate residual methane production, as the different methods have not been compared. In this study, we examined 9 definitions of residual methane production. Records of individual cow methane, dry matter intake (DMI), and energy corrected milk (ECM) were obtained from 379 animals and measured over a 5-d period from 12 batches across 5 yr using the SF6 tracer method and an electronic feed recording system, respectively. The 9 methods of calculating residual methane involved genetic and phenotypic regression of methane production on a combination of DMI and ECM corrected for days in milk, parity, and experimental batch using phenotypes or direct genomic values. As direct genomic values (DGV) for DMI are not routinely evaluated in Australia at this time, DGV for FeedSaved, which is derived from DGV for residual feed intake and estimated breeding value for bodyweight, were used. Heritability estimates were calculated using univariate models, and correlations were estimated using bivariate models corrected for the fixed effects of year-batch, days in milk, and lactation number, and fitted using a genomic relationship matrix. Residual methane production candidate traits had low to moderate heritability (0.10 ± 0.09 to 0.21 ± 0.10), with residual methane production corrected for ECM being the highest. All definitions of residual methane were highly correlated phenotypically (>0.87) and genetically (>0.79) with one another and moderately to highly with other methane candidate traits (>0.59), with high standard errors. The results suggest that direct selection for a residual methane production trait would result in indirect, favorable improvement in all other methane traits. The high standard errors highlight the importance of expanding data sets by measuring more animals for their methane emissions and DMI, or through exploration of proxy traits and combining data via international collaboration.

Agromorphological Characterization Revealed Three Phenotypic Groups in a Region-Wide Germplasm of Fonio (Digitaria exilis (Kippist) Stapf) from West Africa

Fonio is an ancient orphan cereal, cultivated by resource-poor farmers in arid and semi-arid regions of West Africa, who conserved and used the cereal for nutrition and income generation. However, the extent and patterns of phenotypic variation within the fonio germplasm remain scarcely evaluated to inform breeding decisions. In this study, we used alpha lattice design to assess the phenotypic variability of 180 fonio accessions using 20 agro morphological descriptors, including both qualitative and quantitative traits at Bengou research station in 2018 and 2019. Descriptive statistics, combined analysis and multivariate analyses, including principal components analysis (PCA), hierarchical clustering, and multiple factor analysis (MFA) were performed. As results, we found significant differences among fonio accessions and among agro ecological zones of provenance for most of the quantitative traits. Furthermore, highly significant positive correlations were found between grain yield and other yield-related attributes such as harvest index and thousand seeds weight, whereas significant negative correlations were found between grain yield and flowering and maturity times. Clusters analysis revealed three phenotypic groups. Group 1 was characterized by early maturing fonio accessions with higher grain yield. Groups 2 and 3 were characterized by late maturing accessions with intermediate to moderate grain yield. The accessions from Group 1 are candidate for yield improvement and development of fonio lines with enhanced lodging resistance. Accessions from Group 2 and 3 can be improved for yield through marker-assisted selection of best thousand seed weight. This study highlights how traits are correlated within the major phenotypic groups of fonio in West Africa, and we discussed how these groups could be further exploited for improving traits of economic importance. Furthermore, this study exhibited agro morphological descriptors that discriminate fonio accessions and provide useful information for parental selection with economically important agronomic traits.

All sheeps and sizes: a genetic investigation of mature body size across sheep breeds reveals a polygenic nature.

SummaryMature body size is genetically correlated with growth rate, an important economic trait in the sheep industry. Mature body size has been studied extensively in humans as well as cattle and other domestic animal populations but not in sheep. Six‐hundred and sixteen ewes, across 22 breeds, were measured for 28 linear measurements representing various skeletal parts. PCA from these measures generated principal components 1 and 2 which represented 66 and 7% of the phenotypic variation respectively. Two‐hundred and twenty sheep were genotyped on the Illumina Ovine HD beadchip for a GWAS investigating mature body size and linear body measurements. Forty‐six (Bonferroni P < 0.05) SNP associations across 14 chromosomes were identified utilizing principal component 1, representing overall body size, revealing mature body size to have fewer loci of large effect than other domestic species such as dogs and horses. Genome‐wide associations for individual linear measures identified major quantitative trait loci for withers height and ear length. Withers height was associated (Bonferroni P < 0.05) with 12 SNPs across six chromosomes whereas ear length was associated with a single locus on chromosome 3, containing MSRB3. This analysis identified several loci known to be associated with mature body size in other species such as NCAPG, LCORL, and HMGA2. Mature body size is more polygenic in sheep than other domesticated species, making the development of genomic selection for the trait the most efficient option for maintaining or reducing mature body size in sheep.

Meta-analysis of genetic parameters for traits of economic importance for beef cattle in the tropics

Previous genetic and economic evaluation of beef cattle breeding programmes have used genetic and phenotypic parameter estimates obtained in different studies. Such parameters are heterogeneous because they are obtained from different locations, using different sample sizes and estimation methods. The consequence of using such parameters is underestimation or overestimation of potential genetic gains, leading to wrong investment decisions. The objective of the current study was to estimate consensus genetic and phenotypic parameter estimates for beef cattle in the tropics. Meta-analysis of productive, reproductive, adaptation and disease resistance traits was done to obtain weighted traits means, heritabilities, and genetic and phenotypic correlations. Estimates from 208 means, 119 direct and 50 maternal heritability, 42 direct genetic and maternal genetic correlations, 136 genetic and 93 genetic and phenotypic correlations, respectively, were used. A random effect model was used to include the variances within and between studies. Unweighted average direct heritability estimates ranged from 0.26 to 0.32, 0.08 to 0.40, 0.14 to 0.34, 0.18 to 0.67 and 0.30 to 0.35 for growth, reproduction, disease resistance, adaptation and carcass traits, respectively. Weighted heritability estimates for birth weight, weaning weight and yearling weight ranged from 0.18 to 0.26, while those for reproduction traits ranged from 0.02 to 0.09. Weighted maternal heritability estimates for growth traits ranged from 0.07 to 0.11. Carcass, disease resistance and adaptation traits were the least studied despite their great economic importance to beef production in the tropics. Direct maternal heritability estimates for birth, weaning and yearling weights were 0.26, 0.24 and 0.18, while the corresponding maternal heritability estimates were 0.07, 0.11 and 0.08, respectively. Genetic and phenotypic correlations for body weights ranged from 0.43 to 0.88 and 0.32 to 0.80, respectively. Yearling weight and final weight had the highest genetic correlation (0.88). The genetic correlations between body weights and growth rates were moderate to high (0.37 to 0.79). Weaning weight was negatively correlated with post-weaning daily gain (-0.12). Disease resistance traits had low to negative genetic correlations with body weight and growth rate traits (-0.06 to 0.01). Some traits reviewed in the current study were not given a lot of attention, and therefore more focus is required on disease resistance, adaptation and carcass traits. In spite of these limitations, the weighted parameter estimates reported here can be used to add value to beef cattle improvement programmes in the tropics.

Effect of Aging Time on Meat Quality of Longissimus Dorsi from Yunling Cattle: A New Hybrid Beef Cattle.

Simple SummaryBeef is in great demand in many countries. Consumers are more inclined to buy beef with good tenderness, color, flavor, and healthy fatty acid composition. Beef that has been aged is often more suitable for cooking and processing. A research gap exists regarding the analysis of meat quality during the aging process in Yunling cattle, a new hybrid beef cattle bred by Chinese researchers. This study measured a set of indicators of Yunling beef and other two breeds as controls (Simmental cattle, an excellent beef cattle breed used around the world, and Wenshan cattle, a local beef cattle breed in southern China), including the pH, water loss rate, cooking loss, Warner-Bratzler shear force, myofibrillar fragmentation index, inosine 5′-monophosphate, color, and fatty acid profiles. In addition, some growth performance and carcass characteristics were determined. The results showed that the pH, water holding capacity, growth performance, and carcass traits of Yunling and Simmental cattle were basically the same and better, respectively, than those of Wenshan cattle. Aging time had no effect on beef fatty acid composition, with Yunling beef showing a healthier fatty acid profile versus the other two breeds. With increased aging time, the tenderness and color of Yunling beef became more suitable for cooking and sensory characteristics. Therefore, this study suggests that Yunling beef should be used for cooking and processing after aging.The beef aging process is essential for compliance with certain major requisites, such as sensory characteristics for cooking and meat processing. Meat quality analysis of Yunling cattle, a new hybrid beef cattle bred by Chinese researchers, during the aging process, represents a major research gap. To explore Yunling beef initially, indicators associated with meat quality during the aging process of Yunling, Simmental, and Wenshan cattle were measured. In addition, some important economic traits were detected in the three breeds, including growth performance and carcass characteristics. The results showed that the growth performance, carcass traits, pH, and water holding capacity of Yunling and Simmental cattle were basically the same and better, respectively, than those of Wenshan cattle. The proportions of individual fatty acids in Yunling beef were healthier than in the other two breeds. Aging time did not affect the fatty acid profiles of the beef (p > 0.05). The contents of certain fatty acids in the three beef types displayed some differences in terms of days of aging (p < 0.05). The tenderness and meat color were better in the Yunling beef as the aging time increased, indicating that Yunling beef aged for 7 days was more suitable for cooking, exhibiting better sensory characteristics. Thus, a 7-day short-term aging process is very effective in improving the quality of Yunling beef. Our study attempted to fill a gap in the Yunling beef quality analysis during aging, providing further evidence for Yunling beef improvement.

Characterization and expression of MUSTN1 gene from different duck breeds

Muscle growth rate and muscle mass are important economic traits in animal production. Musculoskeletal embryonic nuclear protein 1 (MUSTN1) gene has been implicated in myofusion as well as skeletal muscle growth and repair; however, the exact role and expression of MUSTN1 in different duck breeds are not fully understood. To gain insights into the biological functions of MUSTN1 in skeletal muscle development, the MUSTN1 coding sequence of Pekin ducks (BD) and Cherry Valley ducks (CD) was compared to various other animals using the Editseq in DNAstar and MEGA software. The results showed that the duck had the highest homology with chicken. The RT-qPCR and western blot were performed to estimate the mRNA and protein expression pattern of MUSTN1 in leg muscles of BD and CD at 3 and 6-weeks of age. At 3 weeks of age, the mRNA and protein expression levels of MUSTN1 were significantly higher in BD than in CD (p < 0.05). At 6 weeks, the expression level was higher in BD than in CD. In conclusion, MUSTN1 might play a key role in positive regulation of muscle growth and development of ducks.

Identifying morphological traits associated with vegetative persistence in the perennial ryegrass (Lolium perenne L.) cultivar 'Grasslands Samson'

Perennial ryegrass (Lolium perenne L.) vegetative persistence (maintained herbage growth and survival without reseeding) is an important economic trait for farmers in New Zealand as it decreases the frequency of reseeding pastures. Vegetative persistence is difficult to breed for due to a lack of long-term trials to observe the complex interactions between plant genotype and the environment. In a long-term trial a genetic shift in the sown cultivar population could occur as individual plants with advantageous traits outcompete other plants and survive. The objectives of our study were to investigate the occurrence of a potential genetic shift in a sample (30 plants) of a persistent population of ‘Grasslands Samson’ perennial ryegrass. Persistent plants were collected from a nine-year-old trial at Poukawa, Hawke's Bay. To identify a genetic shift, these plants were compared to a sample of 30 plants sourced from commercial seed of ‘Grasslands Samson’ representing the original population. This study estimated genotypic variation within and between the populations for eight morphological traits after 10 weeks' growth under glasshouse conditions. Phenotypic and genotypic correlations between the traits were estimated. Results showed that the persistent population had significantly (P&lt;0.05) greater means for tiller number, reproductive tiller number, lamina sheath length, and dry weight. Future research studying these traits across farm environments would further understanding of their roles in vegetative persistence of ryegrass.

Sex-Specific Control of Muscle Mass: Elevated IGFBP Proteolysis and Reductions of IGF-1 Levels Are Associated with Substantial Loss of Carcass Weight in Male DU6PxIGFBP-2 Transgenic Mice.

In farmed animals, carcass weight represents an important economic trait. Since we had demonstrated that IGFBP-2 represents a potent inhibitor of muscle accretion in inbred mice, we wanted to quantify the inhibitory effects of IGFBP-2 under conditions of elevated protein mass in growth selected non-inbred mice (DU6P). Therefore, we crossed male DU6P mice with female IGFBP-2 transgenic mice. Male IGFBP-2 transgenic offspring (DU6P/IGFBP-2) were characterized by more than 20% reductions of carcass mass compared to male non-transgenic littermates. The carcass mass in males was also significantly lower (p < 0.001) than in transgenic female DU6P/IGFBP-2 mice, which showed a reduction of less than 10% (p < 0.05) compared to non-transgenic female DU6P/IGFBP-2 mice. Although transgene expression was elevated in the muscle of both sexes (p < 0.001), serum levels were normal in female, but significantly reduced in male transgenic DU6P/IGFBP-2 mice (p < 0.001). In this group, also IGFBP-3 and IGFBP-4 were significantly reduced in the circulation (p < 0.01). Particularly in male transgenic mice, we were able to identify proteolytic activity against recombinant IGFBP-2 included in diluted serum. IGFBP-proteolysis in males correlated with massive reductions of IGF-1 in serum samples and the presence of elevated levels of IGFBP-2 fragments. From our data, we conclude that elevated tissue expression of IGFBP-2 is an essential effector of muscle accretion and may block more than 20% of carcass mass. However, in the circulation, intact IGFBP-2 contained no reliable biomarker content. Notably, for the estimation of breeding values in meat-producing animal species, monitoring of IGFBP-2 expression in muscle appears to be supported by the present study in a model system.

Advances of MSTN Genetic Markers in Domesticated Animals

The myostatin (MSTN) gene is a negative regulator of animal muscle growth and development. This gene not only inhibits muscle cell growth and reduces fat accumulation but also exerts a significant effect on back fat thickness, birth weight and carcass traits. MSTN gene mutation, an important factor that influences economic traits, directly affects the growth and development of animals and consequently the quality of animal products. This paper reviews the structural and functional characteristics of the MSTN gene. The genetic variation of the MSTN gene is then compared among four domestic animals (cattle, sheep, goat and pig) and its correlation with important economic traits is analysed. The mechanism and structural characteristics of MSTN gene mutants are further discussed. This paper provides explication on the application of MSTN gene research in breeding and its importance to the advancement of animal husbandry.

Genome-wide association study reveals the genetic basis of fiber quality traits in upland cotton (Gossypium hirsutum L.)

BackgroundFiber quality is an important economic trait of cotton, and its improvement is a major goal of cotton breeding. To better understand the genetic mechanisms responsible for fiber quality traits, we conducted a genome-wide association study to identify and mine fiber-quality-related quantitative trait loci (QTLs) and genes.ResultsIn total, 42 single nucleotide polymorphisms (SNPs) and 31 QTLs were identified as being significantly associated with five fiber quality traits. Twenty-five QTLs were identified in previous studies, and six novel QTLs were firstly identified in this study. In the QTL regions, 822 genes were identified and divided into four clusters based on their expression profiles. We also identified two pleiotropic SNPs. The SNP locus i52359Gb was associated with fiber elongation, strength, length and uniformity, while i11316Gh was associated with fiber strength and length. Moreover, these two SNPs were nonsynonymous and located in genes Gh_D09G2376 and Gh_D06G1908, respectively. RT-qPCR analysis revealed that these two genes were preferentially expressed at one or more stages of cotton fiber development, which was consistent with the RNA-seq data. Thus, Gh_D09G2376 and Gh_D06G1908 may be involved in fiber developmental processes.ConclusionsThe findings of this study provide insights into the genetic bases of fiber quality traits, and the identified QTLs or genes may be applicable in cotton breeding to improve fiber quality.