Chinese and Japanese population of Chlamys farreri and their reciprocal hybrids were surveyed in isozyme variability at 13 loci by polyacrytamide gel electrophoresis (PAGE). Isozyme banding patterns indicated these hy...Chinese and Japanese population of Chlamys farreri and their reciprocal hybrids were surveyed in isozyme variability at 13 loci by polyacrytamide gel electrophoresis (PAGE). Isozyme banding patterns indicated these hybrids were diploid. Loci that were observed as being monomorphic in inbred populations of C. farreri were also found to be monomorphic in filial progeny; loci that observed to be polymorphic in parental type gen- erations were also polymorphic in hybrid generations. Differences existed among allelic frequency of the four types of cross. Within the reciprocal hybrids the expression of malic enzyme (ME) isozyme was sufficient to distinguishing individual hybrids because of the band, Rf=0.38. However, there were no noticeable variations among all the samples to differentiate one from another. Inbreeding was likely to be the main problem in aqua- culture. The introduction of new broodstock can improve the genetic diversity. Hybrid vigor has manifested to a certain extent in the present study.展开更多
In the present study, formalin-fixed feces, oli-gonucleotide fingerprinting and SRY-gene based sexing were used to construct a family net for giant pandas in the Tang-jiahe Natural Reserve and to assess contemporary g...In the present study, formalin-fixed feces, oli-gonucleotide fingerprinting and SRY-gene based sexing were used to construct a family net for giant pandas in the Tang-jiahe Natural Reserve and to assess contemporary gene flow (migration) in this population. A total of 124 fecal samples were attributed to 37 individuals (22 females and 15 males) that were then analyzed for family relationships. Based on DNA fingerprints, the deduced family net revealed the fol-lowing facts: (i) First-order relatives possessed similarities from 50% to 90%, and similarities between unrelated indi-viduals or distant relatives were as high as 77%, indicating that the Tangjiahe pandas are characterized by high genetic similarity; (ii) 15 matings were identified and 5 ones oc-curred between close relatives, implying that there is poten-tial for inbreeding to impact the pandas; (iii) four mating pairs and 5 offspring presented long distance migrations, demonstrating the intra-reserve habitat is continuous; (iv) four pairs of full sibs (also female-male dyads) dispersed short distance and all of them gave birth to highly inbred offspring, reflecting long distance migration is vital for in-breeding avoidance; (v) 17 adult individuals dispersed short or moderate distance and formed three clusters on the land-scape, indicating that it is necessary to find out whether there is a negative factor impacting the pandas.展开更多
基金Supported by the National "973" Program (G1999012008) and "863" Program (2002AA626020).
文摘Chinese and Japanese population of Chlamys farreri and their reciprocal hybrids were surveyed in isozyme variability at 13 loci by polyacrytamide gel electrophoresis (PAGE). Isozyme banding patterns indicated these hybrids were diploid. Loci that were observed as being monomorphic in inbred populations of C. farreri were also found to be monomorphic in filial progeny; loci that observed to be polymorphic in parental type gen- erations were also polymorphic in hybrid generations. Differences existed among allelic frequency of the four types of cross. Within the reciprocal hybrids the expression of malic enzyme (ME) isozyme was sufficient to distinguishing individual hybrids because of the band, Rf=0.38. However, there were no noticeable variations among all the samples to differentiate one from another. Inbreeding was likely to be the main problem in aqua- culture. The introduction of new broodstock can improve the genetic diversity. Hybrid vigor has manifested to a certain extent in the present study.
基金This work was supported by the National Science Fund for Distinguished Young Scholars(Grant No.30325009)the State Key Basic Research and Development Plan of the P.R.China(Grant No.G2000046906)+1 种基金a special grant for the giant panda from the Sichuan Forestry DepartmentState Forestry Administration of China.
文摘In the present study, formalin-fixed feces, oli-gonucleotide fingerprinting and SRY-gene based sexing were used to construct a family net for giant pandas in the Tang-jiahe Natural Reserve and to assess contemporary gene flow (migration) in this population. A total of 124 fecal samples were attributed to 37 individuals (22 females and 15 males) that were then analyzed for family relationships. Based on DNA fingerprints, the deduced family net revealed the fol-lowing facts: (i) First-order relatives possessed similarities from 50% to 90%, and similarities between unrelated indi-viduals or distant relatives were as high as 77%, indicating that the Tangjiahe pandas are characterized by high genetic similarity; (ii) 15 matings were identified and 5 ones oc-curred between close relatives, implying that there is poten-tial for inbreeding to impact the pandas; (iii) four mating pairs and 5 offspring presented long distance migrations, demonstrating the intra-reserve habitat is continuous; (iv) four pairs of full sibs (also female-male dyads) dispersed short distance and all of them gave birth to highly inbred offspring, reflecting long distance migration is vital for in-breeding avoidance; (v) 17 adult individuals dispersed short or moderate distance and formed three clusters on the land-scape, indicating that it is necessary to find out whether there is a negative factor impacting the pandas.
