The fact that interspecific hybrids are usually sterile or with diminished reproductive capacity due to problems with gonad development and chromosome pairing have been recognized from the beginnings of the scientific...
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The fact that interspecific hybrids are usually sterile or with diminished reproductive capacity due to problems with gonad development and chromosome pairing have been recognized from the beginnings of the scientific concepts of *** ascertain for postzygotic reproductive isolating mechanisms of hybrids between female Crassostrea hongkongensis and male ***,45 interspecific hybrid families by the method of nested design were conducted as the experimental materials in July *** the gonad of progenies developed to mature by one year culture,we examined the viability of 1640 F hybrids in all families.A certain extent of polymorphism for gonad colors of hybrids was observed,including milk white,saffron yellow,sandy beige,and grayness four major color types,and these of corresponding with female,hermaphrodic,male and asexual,respectively. That is,the gonad color was *** patterns of hybrid sterile were classified as below three types:（1） Complete sterile:the majority of hybrids（65.26%） were sterile without gametes.（2） Partial fertile:several female hybrids（19.65%） were fertile with 0.21%normal oogenesis,a bit of hermaphroditic（1.40%） were fertile both 0.06%normal oogenesis and 0.04%normal spermatogenesis,while a few of male hybrids（5.06%） were sterile with 0.55% normal spermatogenesis.（3） Complete fertile:only a small of female hybrids（8.64%） was completely fertile with 33.72%normal *** and gametes count analyses of the hybrid gonad revealed that the sterility mode was defined as "sperm rare or absence",and it was according with the "Haldane's rule".To our knowledge,the present finding is a novel example of hybrid sterility in the Crassostrea species.
Based on the EST sequence of mantle cDNA library of Hyriopsis cumingii,the complete cDNA of Hyriopsis cumingii IRF-2(HcIRF-2) gene was cloned by rapid amplification of cDNA ends (RACE),and partial DNA sequence and it&...
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Based on the EST sequence of mantle cDNA library of Hyriopsis cumingii,the complete cDNA of Hyriopsis cumingii IRF-2(HcIRF-2) gene was cloned by rapid amplification of cDNA ends (RACE),and partial DNA sequence and it's 5'-flanking region was amplified with PCR and genome walking technique *** HcIRF-2 full-length cDNA sequence was 2688 bp including a 110 bp 5'-untranslated region,a 1588 bp 3'-untranslated region and an open reading frame(ORF) 990 bp in length,which encodes for 329 amino acids with the predicted molecular weight of 37.6 KDa and the isoelectric point of *** sequence length of intron I and 5'-flanking region was 465bp and 1669 bp *** analysis of the 5'-flanking region revealed that it contained several transcription regulation elements such as AP1、CdxA、HSF、NIT2 and *** amino acid sequences have highly conserved DBD structure in N-terminal that contains characteristic repeats of six tryptophan *** analysis of amino acid sequences indicated that HcIRF-2 is overall 24.3-32.6%identical to homologous proteins from mammals,avians,amphibians,and fishs,with 56.6-62.8%identity at the level of the N-terminal DBD and only 9.4-23.1%identity in the *** trees showed that each type of IRF clustered together as a subgroup,and IRF-2 of Hyriopsis cumingii was clustered together with IRF-2 and IRF-1 of other species,twelve SNPs were obtained through direct sequencing IRF-2 gene of Hyriopsis cumingii from wild population(YS) and cultured population(YZ),and we investigated the association of these polymorphic locis with resistance *** them,-1918C-T SNP、-3786G-T SNP were significant difference of the allelic frequency between the wild population and the cultured population(P<0.05);-3917T-C SNP were significant difference of the genotypes frequency between the wild population and the cultured population(P<0.05);-4034C-T SNP were significant difference of the genotypes frequency and allelic freq
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