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1.
South polar skuas, SPS, (Catharacta maccormicki) and brown skuas, BS, (C. antarctica lonnbergi) are regarded as opportunistic predators. When breeding in sympatry, BS feed mainly on penguin eggs and chicks, while SPS
forage almost exclusively at sea. The objective of this study was to determine the diet composition of adult SPS and BS breeding
in sympatry, in order to assess food resource partitioning between these species. The total number of food items consumed
was 375 for BS and 682 for SPS in 1992–93, and 427 for BS and 579 for SPS in 1995–96. The pellets composition was significantly
correlated between skua species for the same breeding season (r
s = 0.67, p = 0.0062 and r
s = 0.81, p < 0.001, for 1992–93 and 1995–96, respectively), and between breeding seasons for the same skua species (r
s = 0.71, p = 0.001 and r
s = 0.81, p < 0.001, for SPS and BS, respectively). Trophic niche breadth of BS was wider than that of SPS (B
A(BS) = 0.28 and B
A(SPS) = 0.24; Z = 7.67; p < 0.001). The trophic niche overlap between BS and SPS was over 65% in both breeding seasons. In agreement with other studies
on the diet of these skua species in situations of sympatry, SPS consumed more fish and BS consumed more birds. 相似文献
2.
We studied habitat choice, diet, food consumption and somatic growth of Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) during the ice-covered winter period of a subarctic lake in northern Norway. Both Arctic charr and brown trout predominantly
used the littoral zone during winter time. Despite very cold winter conditions (water temperature <1°C) and poor light conditions,
both fish species fed continuously during the ice-covered period, although at a much lower rate than during the summer season.
No somatic growth could be detected during the ice-covered winter period and the condition factor of both species significantly
declined, suggesting that the winter feeding rates were similar to or below the maintenance requirements. Also, the species
richness and diversity of ingested prey largely decreased from summer to winter for both fish species. The winter diet of
Arctic charr <20 cm was dominated by benthic insect larvae, chironomids in particular, and Gammarus lacustris, but zooplankton was also important in December. G. lacustris was the dominant prey of charr >20 cm. The winter diet of brown trout <20 cm was dominated by insect larvae, whereas large-sized
trout mainly was piscivorous, feeding on juvenile Arctic charr. Piscivorous feeding behaviour of trout was in contrast rarely
seen during the summer months when their encounter with potential fish prey was rare as the small-sized charr mainly inhabited
the profundal. The study demonstrated large differences in the ecology and interactions of Arctic charr and brown trout between
the winter and summer seasons. 相似文献
3.
The present study focuses on the geographic distribution and biodiversity of the Chlorococcales in Patagonian lakes, covering a latitudinal transect. Two different approaches are considered (a) a review of the historical
records of Chlorococcales in Patagonia and (b) the analysis of the morphology-based species diversity, ecological remarks, and geographic distribution
of the chlorococcalean species recorded in 33 aquatic environments during surveys 2007 and 2008. A total of 308 chlorococcalean
species were recorded throughout a 60-year period in Patagonian freshwater systems, encountering the highest chlorococcalean
richness in lakes and shallow lakes located in the more intensively sampled areas. In our surveys 2007–2008, 72 chlorococcalean
taxa were registered, among which 80% are worldwide distributed, about 19% are restricted to cold temperate areas in both
hemispheres and one species (Pediastrum patagonicum) is one of the taxa probably endemic for Patagonia. The chlorococcalean richness in relation to the environmental factors,
revealed that it is directly correlated with the trophic status of the water bodies (chl a: r = 0.52 and DIN: r = 0.47; P < 0.05). The latitude was inversely correlated with the species richness (r = −0.40; P < 0.05), and the chlorococcalean biodiversity of the Andean lakes (mean value: 3.64) was significantly lower (P = 0.0022) than that of the lakes from the Patagonian Plateau (mean value: 9.62). In this study we observed a decreasing trend
in the biodiversity of Chlorococcales with increasing latitude, which fits in the existing ecological pattern described for different groups of organisms. 相似文献
4.
Recent studies have identified common variants in or near GC, CYP2R1 and NADSYN1/DHCR7 to be associated with 25-hydroxyvitamin D [25(OH)D] levels in European populations. We aimed to examine whether these variants
also influence 25(OH)D levels in Chinese. Seven common variants were successfully genotyped and tested for associations with
plasma 25(OH)D levels in a population-based cohort of 3,210 Chinese Hans from Beijing and Shanghai. Six common variants at
GC (rs4588, rs7041, rs2282679 and rs1155563) and NADSYN1/DHCR7 (rs3829251 and rs1790349) loci were all significantly associated with lower plasma 25(OH)D levels (−0.036 ≤ β ≤ −0.076 per risk-allele, P ≤ 5.7 × 10−5), while CYP2R1-rs2060793 showed a trend toward association with 25(OH)D levels in the Shanghai subpopulation (P = 0.08), but not in the Beijing subpopulation (P = 0.82). Haplotype-based association analyses of the four GC variants showed that only the haplotype that contained all risk-alleles (TACC) was significantly associated with lower plasma
25(OH)D levels (β = −0.085, P = 2.3 × 10−9), while the haplotype containing the risk-alleles of rs4588 and rs2282679 (TATC) was marginally associated with lower 25(OH)D
levels (β = −0.054, P = 0.0562) when compared with GCTA haplotype carrying the four protective alleles. Most notably, conditional analyses showed
that only GC-rs4588 and GC-rs2282679 (r
2 = 0.97) remained significantly associated with 25(OH)D concentrations (P ≤ 1.9 × 10−5) after adjusting for the other two SNPs in GC. In conclusion, GC and NADSYN1/DHCR7 loci individually and collectively contribute to variation in plasma vitamin D levels in Chinese Hans. 相似文献
5.
Genetic engineering of lactic acid bacteria (LAB) requires a reliable gene expression system. Especially, a stable promoter
is an important genetic element to induce gene expression in such a system. We report on a novel tuf promoter (Ptuf) of Lactococcus lactis subsp. lactis IL1403 that was screened and selected through analysis of previously published microarray data. Ptuf activity was examined and compared with three other known lactococcal promoters (PdnaJ, PpfkA, and Pusp45) using different bacteria as expression hosts. Each promoter was, respectively, fused to the promoterless and modified bmpB gene as a reporter, and we estimated promoter activity through BmpB expression. All promoters were active in IL1403, and
Ptuf activity was strongest among them. The activity of each promoter differed by host bacteria (Lactobacillus plantarum Lb25, Lactobacillus reuteri ATCC23272, and Escherichia coli Top10F’). Ptuf had the highest activity in IL1403 when growth reached late log phase. The activity of each promoter correlated with the
expression of each cognate gene in the microarray data (R
2 = 0.7186, P = 0.06968). This study revealed that novel food-grade promoters such as IL1403 Ptuf can be selected from microarray data for food-grade microorganisms and Ptuf can be used to develop a reliable gene expression system in L. lactis. 相似文献
6.
Xianyong Lan Xinsheng Lai Zhuanjian Li Jing Wang Chuzhao Lei Hong Chen 《Molecular biology reports》2010,37(1):441-449
HESX1 plays a key role in the development of the forebrain and pituitary gland and produces potential effects on performance
traits. The objective of this study was to detect and assess the associations of the possible polymorphisms of six loci within
HESX1 gene with performance traits in Chinese 1,119 goats. Only one novel SNP (NM_001494116:g.307049A > G) locating on IVS1 + 348A > G
was identified and detected by HaeIII forced-RFLP-PCR. The frequencies of allele “G” varied from 0.025 to 0.245 in analyzed populations with the Hardy–Weinberg
equilibrium (P > 0.05). Genotypic and allelic frequencies were found to be significantly different in four breeds (χ2 = 147.674, df = 6, P < 0.001; χ2 = 157.250, df = 3, P < 0.001, respectively), implying that the distribution of genotypic and allelic frequencies of goat HESX1 gene was significantly associated with different goat utilities (cashmere, meat and dairy). Association analysis results
revealed no significant effects of caprine HESX1 gene on body sizes in XNSN population (P > 0.05) and cashmere traits in IMWC population (P > 0.05). Significant statistical of HESX1 gene with body weight was found (*P < 0.05). The genotype AA showed significantly higher body weight than those of AG in 2-year-old age (*P < 0.05), while the AA genotype was senior to AG genotype in 4-year-old body weight trait (*P < 0.05). These suggestions indicated that the HESX1 gene has significant effect on goat body weight depending on ages, which is accordance with the function repressor of the
HESX1. 相似文献
7.
Z. Y. Xu H. Yang Y. Z. Xiong C. Y. Deng F. E. Li M. G. Lei B. Zuo 《Molecular biology reports》2010,37(7):3609-3613
In this study, two novel SNPs (EU743939:g.5174T>C in intron 4 and EU743939:g.8350C>A in intron 7) in TNNI1 and one SNP (EU696779:g.1167C>T in intron 3) in TNNI2 were identified by PCR–RFLP (PCR restriction fragment length polymorphism) using XbaI, MspI and SmaI restriction enzyme, respectively. The allele frequencies of three novel SNPs were determined in the genetically diverse
pig breeds including ten Chinese indigenous pigs and three Western commercial pig breeds. Association analysis of the SNPs
with the carcass traits were conducted in a Large White × Meishan F2 pig population. The linkage of two SNPs (g.5174T>C and g.8350C>A) in TNNI1 gene had significant effect on fat percentage. Besides these, the g.5174T>C polymorphism was also significantly associated
with skin percentage (P < 0.05), shoulder fat thickness (P < 0.05) and backfat thickness between sixth and seventh ribs (P < 0.05). The significant effects of g.1167C>T polymorphism in TNNI2 gene on fat percentage (P < 0.01), lean meat percentage (P < 0.05), lion eye area (P < 0.05), thorax–waist backfat thickness (P < 0.01) and average backfat thickness (P < 0.05) were also found. 相似文献
8.
Yi-Ying Liao Xing-Yu Yang Timothy J. Motley Jin-Ming Chen Qing-Feng Wang 《Conservation Genetics》2011,12(5):1357-1365
Ceratopteris thalictroides (L.) Brongn. (Parkeriaceae) is a difficult fern species to taxonomically classify. Three cryptic species were revealed in
the previous studies, referred to as the north type, the south type, and the third type. Because much of the distribution
range of C. thalictroides in China was not included in the sampling of the previous studies, the taxonomic complexity of C. thalictroides in China remained uncertain. In order to identify the uncharacterized cryptic species, we examined four chloroplast DNA (cpDNA)
non-coding regions and compared sequence variation within this species complex. Sequence data were obtained from 143 individuals
in 24 populations throughout the natural distribution of the species in China. Nineteen haplotypes were identified. Molecular
systematic and phylogeographical analyses revealed two genetically distinct clusters of cpDNA haplotypes in China. One cluster
included haplotypes associated with the north type, and another with the south type cryptic species. The N
ST value was significantly higher than the G
ST value (N
ST = 0.768 > G
ST = 0.434, P < 0.05), indicating the presence of a significant phylogeographical structure of C. thalictroides in China. The results of AMOVA analysis showed a significant inter-group differentiation (F
ST = 0.918; P < 0.001). Analyses based on different, but complementary methods suggest that in China, C. thalictroides contains only two of the cryptic species (the north and south types). Two haplotypes, H8 and H17, of the interior node in
the minimum-spanning network (MSN) of cpDNA haplotypes are widespread. The origin of the widespread haplotypes in China may
have resulted from long-distance dispersal to China. 相似文献
9.
Insulin-like growth factor II (IGF-II) is involved in the regulation of somatic growth and metabolism in many fishes. IGF-II is an important candidate gene for growth traits in fishes and its polymorphisms were associated with the growth traits.
The aim of this study is to screen single nucleotide polymorphisms (SNPs) of the largemouth bass (Micropterus salmoides) IGF-II gene and to analyze potential association between IGF-II gene polymorphisms and growth traits in largemouth bass. Four SNPs (C127T, T1012G, C1836T and C1861T) were detected and verified
by DNA sequencing in the largemouth bass IGF-II gene. These SNPs were found to organize into seven haplotypes, which formed 13 diplotypes (haplotype pairs). Association
analysis showed that four individual SNPs were not significantly associated with growth traits. Significant associations were,
however, noted between diplotypes and growth traits (P < 0.05). The fish with H1H3 (CTCC/CGCC) and H1H5 (CTCC/TTTT) had greater body weight than those with H1H1 (CTCC/CTCC), H1H2
(CTCC/TGTT) and H4H4 (TGCT/TGCT/) did. Our data suggest a significant association between genetic variations in the largemouth
bass IGF-II gene and growth traits. IGF-II SNPs could be used as potential genetic markers in future breeding programs of largemouth bass. 相似文献
10.
The present study was done to determine the modulation effect(s) of polymorphisms of XRCC1, GSTM1, and GSTT1 on concentration of serum testosterone in females exposed to natural sour gas. Also we examine whether chronic exposure to
natural gas containing sulfur compounds act as natural selection force on XRCC1 polymorphisms. The present study was performed on 68 healthy unrelated female students living in polluted areas of MIS. Also
for investigating the effect of natural selection on XRCC1 polymorphism, a study was performed on two groups of healthy individuals
of MIS citizens. The first and second groups including 94 (age range 30–85 years) and 187 individuals (age range 5–20 years),
respectively. First and second groups were born and were not born in contaminated areas of the MIS, respectively. There was
no significant difference between genotypes of XRCC1 for concentration of serum testosterone. Although GSTT1-null genotype had higher level of serum testosterone in comparison with the present genotype (t = 2.392, df = 66, P = 0.023), a borderline difference between genotypes of GSTM1 for serum testosterone was observed (t = 1.928, df = 66, P = 0.058). Analysis of variance revealed significant difference between combination genotypes of GSTM1 and GSTT1 for serum testosterone (F = 4.167; df = 3, 64; P = 0.009). The Duncan post hoc test indicated that the combination genotype of “present GSTM1/null GSTT1” had significant higher level of testosterone. There is no evidence that XRCC1 polymorphisms have advantage/disadvantage when population exposed to natural sour gas. The polymorphisms of GSTM1 and GSTT1 modulate serum testosterone concentration in young females exposed to natural sour gas. 相似文献
11.
Xuewen Xu Haifang Qiu Zhi-Qiang Du Bin Fan Max F. Rothschild Fan Yuan Bang Liu 《Molecular biology reports》2010,37(1):451-459
CRP3 is the muscle-specific form of the cysteine and glycine-rich protein family and plays an important role in myofiber differentiation.
Here we isolated and characterized its coding gene CSRP3 from porcine muscle. Phylogenic analyses demonstrated that CSRP3 diverged first and is distinguished from two other members, CSRP1 and CSRP2. CSRP3 mRNA was up-regulated during the development of porcine embryonic skeletal muscle, indicating its potential importance in
muscle growth. Genetic variant analyses detected multiple variations in an approximately 400 bp region covering exon 4 and
its downstream intron, and two haplotypes were identified by sequencing. One of synonymous substitutions C1924T was used for
linkage and association analyses. It was revealed that the substitution of C1924T had significant associations with firmness
(P < 0.01), Lab Loin pH, Off Flavor Score and Water Holding Capacity (P < 0.05), and a suggestive effect (P < 0.1) on Flavor Score and Average Glycolytic Potential in a Berkshire × Yorkshire F2 population. The association analyses
results agreed with the gene’s localization to a QTL region for meat quality traits on porcine chromosome 2p14-17 demonstrated
by both linkage mapping and RH mapping. These results provide fundamental evidence for CSRP3 as a functional candidate gene affecting pig meat quality. 相似文献
12.
Wei Dong Li Ning Wei-dong Lu Cui-cui Li Rui-peng Chen Xiao-ning Jia Lin Wang Li-zhong Guo 《World journal of microbiology & biotechnology》2009,25(4):633-638
The tumor-inhibitory and liver-protective effects of crude extracellular polysaccharides (EPS) extracted from the liquid mycelial
culture of the mushroom Phellinus igniarius were studied in mice. The mice were injected with murine sarcoma S180 and murine hepatoma H22. Crude EPS at 100, 200, 400 mg kg−1 body weight was administered to EPS groups each day in the twelve consecutive days. The result showed that EPS 200 mg kg−1 body weight significantly inhibited S180 and H22 at 65.0 and 46.3%, respectively. Moreover, EPS could not only keep the numbers
of WBC, RBC, PLT and the concentration of HGB in a normal range, but also normalize the activities of AST, ALT and ALP. For
example, in EPS-treated mice, AST significantly reduced with the percentage of A/G reverse in S180 (P < 0.05) and H22 (P < 0.01) when the mice took EPS 200 mg kg−1 body weight. In conclusion, it was remarkable that P. igniarius EPS exhibited antitumor activity related to dosage and protected liver function by sustaining the blood routine as well as
keeping the blood biochemical indexes normal. 相似文献
13.
Walid Nosir Jim McDonald Steve Woodward 《Journal of industrial microbiology & biotechnology》2011,38(1):21-27
Fusaric acid (FA) (5-n-butylpuridine 2-carboxyl acid), a highly toxic secondary metabolite produced by Fusarium oxysporum strains, plays a significant role in disease development. The abilities of three F. oxysporum f. sp. gladioli (Massey) Snyder and Hansen isolates (G010; 649-91; and 160-57) to produce FA in infected Gladiolus corm tissues was evaluated in vitro in relation to the presence of two biological control agents, Trichoderma harzianum T22, and Aneurinobacillus migulanus. Pathogenicity tests were used to differentiate between the abilities of the F. oxysporum strains to secrete FA. FA was identified using LC/MS and quantified using HPLC. Isolate G010 was significantly more virulent
(P < 0.01) on Gladiolus grandiflorus corms; it secretes 1.8 μM FA/g fresh weight corm into inoculated Gladiolus. Moreover, G010 was the only isolate that produced FA among the three examined isolates. There was a correlation between
the corm lesion area and the FA secretion ability of F. oxysporum f. sp. gladioli (P < 0.001; r
2 = 0.96). No FA was detected in PDA cultures of F.oxysporum f. sp. gladioli isolates. The presence of T. harzianum T22 appeared to prevent FA secretion into the corms. In the presence of A. migulanus, however, the amount of FA secreted into the corm tissues increased. These results support the use of T. harzianum as an effective biological control agent against F. oxysporum f. sp. gladioli. 相似文献
14.
Polymorphisms of caprine <Emphasis Type="Italic">GDF</Emphasis>9 gene and their association with litter size in Jining Grey goats 总被引:1,自引:0,他引:1
Feng T Geng CX Lang XZ Chu MX Cao GL Di R Fang L Chen HQ Liu XL Li N 《Molecular biology reports》2011,38(8):5189-5197
The exons 1, 2 and flanking region of growth differentiation factor 9 (GDF9) gene in five randomly selected does of Jining Grey, Boer and Liaoning Cashmere goats were amplified and analyzed. Thirteen
nucleotide differences were identified in GDF9 gene between sheep (AF078545) and goats. Four SNPs (G3288A in intron 1, G423A, A959C [Gln320Pro] and G1189A [Val397Ile]
in exon 2) were detected in four goat breeds with different prolificacy, in which G3288A was a new SNP in goats. The results
showed that loci 3288, 423 and 1189 in Boer goats, loci 3288 and 423 in Guizhou White goats, loci 423 and 1189 in Liaoning
Cashmere goats were all in complete linkage disequilibrium (D′ = 1, r
2 = 1), respectively. In moderate (Boer goat) and low prolificacy (Liaoning Cashmere goat) breeds, linkage analysis indicated
that there were more fervent linkage disequilibrium among loci 3288, 423 and 1189 than high prolificacy (Jining Grey and Guizhou
White goats) breeds. For the 959 locus, the genotype distribution showed obvious difference between high prolificacy breeds
and moderate or low prolificacy breeds (P < 0.05 or P < 0.01). The Jining Grey goat does with genotype CC or AC had 0.81 (P < 0.01) or 0.63 (P < 0.01) kids more than those with genotype AA, respectively. The present study preliminarily showed an association between
allele C at 959 locus of GDF9 gene and high litter size in Jining Grey goats. These results provide further evidence that the GDF9 gene may be significantly correlated with high prolificacy in goats. 相似文献
15.
Gong P Li J Chi W Wang J Yao T Zhang K Gao X Zhang F 《Cellular and molecular neurobiology》2011,31(8):1163-1169
Catechol-O-methyltransferase (COMT) and dopamine-beta hydroxylase (DBH) are key enzymes to breakdown dopamine. Some previous studies
have indicated that val158met in COMT and 19 bp insertion/deletion in 5′ flank of DBH are related to the performance of executive function. To further investigate the associations of the two genes with executive
function, we performed a population-based study in a Chinese Han population. The results indicated that val158met in COMT and the 19 bp insertion/deletion of DBH were associated with the average reaction time of response inhibition in female group (P = 0.01, P = 0.03), respectively. Furthermore, there was a significant interaction of the two genes on the reaction time (P = 0.006). This present study suggests that not only do COMT and DBH influence independently on response inhibition in females, but also exert a significant interaction on response inhibition. 相似文献
16.
Sandip Madhusudan Swain Chandrasekar Singh Venkatesan Arul 《World journal of microbiology & biotechnology》2009,25(4):697-703
Occurrence of widespread epizootics among larval and cultured shrimp has put on viable preventive approaches such as application
of probiotics on a high priority in aquaculture. In the present study, four probiotics bacteria were isolated from marine
fish and shrimp intestine based on the antagonistic activity and nonpathogenic to the host. The isolates of probiotics strains
Streptococcus phocae PI80, Enterococcus faecium MC13, Lactococcus garvieae LC149, B49 and one commercial probiotics (ECOFORCE) were fed to post larvae of Penaeus monodon obtained from two different hatcheries to analyze the growth and protection against Vibrio harveyi and V. parahaemolyticus. Growth of P. monodon post larvae fed with probiotic strain S. phocae PI80 was significantly (P < 0.001) higher when compared with control and other three strains in both experiments. The treatment of post larvae with
B49 reduced the growth as well as Specific growth rate. Among the three probiotic strains S. phocae PI80 and E. faecium MC13 have effectively inhibited the pathogens. In experiment I high survival (92%) were observed in S. phocae PI80 treated post larvae when challenged with Vibrio harveyi followed by E. faecium MC13 (84%), B49 (76%) and ECOFORCE (68%) but PI80 did not protect the post larvae in the same experiment when they were exposed
to V. parahaemolyticus. The probiotic isolate of MC13 has protected the post larvae against V. parahaemolyticus when compared to other probiotics and control. Similarly in the second experiment feeding of S. phocae enhanced the survival of larvae when challenged with V.
harveyi. The laboratory studies proved that bacterial probionts S. phocae and E. faecium isolated from shrimp and brackishwater fish has potential applications for controlling pathogenic vibriosis in shrimp culture. 相似文献
17.
Commiphora wightii is a medicinally important endangered species endemic to the Thar Desert of Rajasthan, India and adjoining areas of Pakistan.
The populations of this species are declining sharply because of its extensive use as a natural herb. Random amplified polymorphic
DNA analysis was conducted to find the genetic variation among 7 populations of C. wightii. Of the 100 random primers screened, 44 primers yielded 220 loci. Statistical analysis indicated low genetic diversity (H
pop = 0.0958; I = 0.1498; mean polymorphic loci = 14.28%), and high genetic differentiation among the populations (G
ST = 0.3990; AMOVA Φ
ST of 0.3390; Bayesian θ
(II) = 0.3002). The low genetic diversity may be due to geographic isolation and restricted gene flow (N
m = 0.7533) between the fragmented populations. Unsustainable utilization of the plant has fragmented the population continuum
which served the purpose of genetic exchange between populations. Mantel’s test was performed which revealed a highly significant
positive correlation between genetic and geographic distance (r
2 = 0.614, P = 0.023) among the populations studied. Low variation can also be attributed to poor seed setting and the slow growth pattern
of the species, which is also an apomict. In UPGMA dendrogram the Commiphora wightii samples were divided into two major and one minor cluster. These findings can serve as a guide to preserving the genetic
resources of this medicinal plant species. 相似文献
18.
The hypothalamic gonadotropin-releasing hormone receptor (GnRHR) plays an essential physiological role in reproductive function, which triggers the synthesis and release of luteinizing
hormone and follicle stimulating hormone in the pituitary. The objective of this study was to investigate the effects of polymorphisms
of GnRHR gene on the quality of fresh and frozen semen in Holstein bulls. The PCR-RFLP method was applied to detect G286A and T340C
transitions determining MboII and BspMI polymorphisms, respectively, in the exon I of bovine GnRHR gene and evaluated its associations with sperm quality traits in 131 Holstein bulls. In polymorphic locus 286, bulls with
the GA genotype had significantly higher sperm motility in frozen semen (FMOT) than GG genotype (P < 0.01). In polymorphic locus 340, bulls with heterozygote CT genotype had significantly higher sperm motility (MOT), semen
volume per ejaculate (VOL), and lower abnormal spermatozoa rate (ASR) than homozygote TT genotype (P < 0.05). Bulls contained one A allele or C allele had a favorable, positive effect on sperm quality traits. These results
indicate that GnRHR gene can be a potential marker for improving sperm quality traits, and imply that bulls with GA or CT genotype should be
selected in breeding program. 相似文献
19.
F. Y. Chen H. Niu J. Q. Wang C. Z. Lei X. Y. Lan C. L. Zhang M. J. Li L. S. Hua J. Wang H. Chen 《Molecular biology reports》2011,38(1):243-248
DLK1 and CLPG were located in DLK1-GTL2 imprinted cluster. They all affected muscle growth and meat tenderness. The functional importance of DLK1 and CLPG imply that the variation of the genes could affect the growth traits of animal. PCR-SSCP and sequencing were used to analyze
the four loci of DLK1 gene and CLPG gene in 1109 individuals, which belong to eight breeds/species of bovidae, including cattle, buffalo and yak. A synonymous
mutation (C451T) was detected in exon 5 of DLK1 in Qinchuan cattle, but didn’t change significantly with phenotypic traits. Three genotypes AA, AB and AC of CLPG were identified in Jiaxian cattle. The associations analyst of different genotypes showed that the individuals with genotypes
AA and AC had a greater body weight and longer body length than those with genotype AB (P < 0.05 and P < 0.01, respectively); the AA individuals were different from those AB (P < 0.05) in the circumference of cannon bone. No polymorphism was observed in the other populations at other loci. These results
were in agreement with the homology analysis: DLK1 and CLPG genes were in a highly conserved. 相似文献
20.
Michael H. Meeuwig Christopher S. Guy Wade A. Fredenberg 《Environmental Biology of Fishes》2011,90(4):367-378
Lacustrine-adfluvial bull trout, Salvelinus confluentus, migrate from spawning and rearing streams to lacustrine environments as early as age 0. Within lacustrine environments,
cover habitat provides refuge from potential predators and is a resource that is competed for if limiting. Competitive interactions
between bull trout and other species could result in bull trout being displaced from cover habitat, and bull trout may lack
evolutionary adaptations to compete with introduced species, such as lake trout, Salvelinus namaycush. A laboratory experiment was performed to examine habitat use and interactions for cover by juvenile (i.e., <80 mm total
length) bull trout and lake trout. Differences were observed between bull trout and lake trout in the proportion of time using
cover (F
1,22.6 = 20.08, P < 0.001) and bottom (F
1,23.7 = 37.01, P < 0.001) habitat, with bull trout using cover and bottom habitats more than lake trout. Habitat selection ratios indicated
that bull trout avoided water column habitat in the presence of lake trout and that lake trout avoided bottom habitat. Intraspecific
and interspecific agonistic interactions were infrequent, but approximately 10 times greater for intraspecific interactions
between lake trout. Results from this study provide little evidence that juvenile bull trout and lake trout compete for cover,
and that species-specific differences in habitat use and selection likely result in habitat partitioning between these species. 相似文献