Using ISSR technique to analyze the diversity and genetic relationship of germplasm resources in 39 Prunus mume Sibe. et Zucc., the result showed that 10 primers were screened with high resolution from 51 primers, 120...Using ISSR technique to analyze the diversity and genetic relationship of germplasm resources in 39 Prunus mume Sibe. et Zucc., the result showed that 10 primers were screened with high resolution from 51 primers, 120 fragments were amplified, of which 98 were polymorphic loci, accounting for 81.67% of total. Tested materials were divided into 3 classes, as was fundamentally accorded with the traditional classification base on horticulture. There was no obvious difference in geographic relationship among the clustering results.展开更多
While food sharing among related individuals can be explained by kin selection, food sharing be- tween unrelated individuals has been more of an evolutionary puzzle. The food-for-sex hypothesis provides an explanation...While food sharing among related individuals can be explained by kin selection, food sharing be- tween unrelated individuals has been more of an evolutionary puzzle. The food-for-sex hypothesis provides an explanation for the occurrence of food sharing among nonkin. However, little is known about the socio-ecological factors that can promote such a commodity exchange. A species mating system is a factor potentially influencing food-for-sex patterns of behavior. Here, we compared wolves, which form pair-bonds, with dogs, which are typically promiscuous in freeranging contexts, to investigate the effect of reproductive stages on the behavior around a food source in 2 different contexts. Furthermore, we considered the roles of both the males and the fe- males in the potential food-for-sex exchange. Results indicate that in both species and for both sexes the breeding period promotes decreased aggression. Additionally, females were more per- sistent in their attempts to access the food and were able to monopolize the resource more when in heat as compared to outside the breeding period. Finally, in dogs, but not wolves, females spent more time in proximity to the male＇s bone and had a shorter latency to start eating it when in heat. Overall, this study demonstrates that the food-for-sex hypothesis plays a part in intersexual food sharing in canids, and highlights the role of females in the interaction. These effects were especially the case in dogs, suggesting a potential effect of mating system on food-for-sex responses展开更多
Plant cystatins or phytocystatins are cysteine proteinase inhibitors exist widely in different plant species. Because they can kill insects by inhibiting the digestive function of the cysteine proteinase in gut, they ...Plant cystatins or phytocystatins are cysteine proteinase inhibitors exist widely in different plant species. Because they can kill insects by inhibiting the digestive function of the cysteine proteinase in gut, they are believed to play an important role in plant’s defense against pests. Phytocystatins contain the conserved QXVXG motif and show some features on their sequence different to animal cystatins. After sequencing the protein directly and the cDNA clone, a large number of plant cystatins have been characterized. A multialignment with BLAST software and a detail analysis of 38 phytocystatins show that phytocystatins possess a specific conserved amino acid sequence [LRVI]-[AGT]-[RQKE]-[FY]- [AS]-[VI]-X-[EGHDQV]-[HYFQ]-N different to the conserved sequence demonstrated by Margis in 1998. This conserved sequence can be enough to detect with exclusivity phytocystatin sequences on protein data banks. A classification of these phytocystatins is performed and they can be divided into 3 groups according to their features on amino acid sequence, and the group-I can be still divided into 3 subgroups based on the feature of their amino acid and genomic sequence. By the CLUSTALX software, the most conserved nucleotide sequences of phytocystatins were found, which could be used to design the degenerate premiers to search new phytocystatins with PCR reaction.展开更多
基金Supported by Science and Technology Planning Project of Guang-dong Province (2007A020300002-6)~~
文摘Using ISSR technique to analyze the diversity and genetic relationship of germplasm resources in 39 Prunus mume Sibe. et Zucc., the result showed that 10 primers were screened with high resolution from 51 primers, 120 fragments were amplified, of which 98 were polymorphic loci, accounting for 81.67% of total. Tested materials were divided into 3 classes, as was fundamentally accorded with the traditional classification base on horticulture. There was no obvious difference in geographic relationship among the clustering results.
文摘While food sharing among related individuals can be explained by kin selection, food sharing be- tween unrelated individuals has been more of an evolutionary puzzle. The food-for-sex hypothesis provides an explanation for the occurrence of food sharing among nonkin. However, little is known about the socio-ecological factors that can promote such a commodity exchange. A species mating system is a factor potentially influencing food-for-sex patterns of behavior. Here, we compared wolves, which form pair-bonds, with dogs, which are typically promiscuous in freeranging contexts, to investigate the effect of reproductive stages on the behavior around a food source in 2 different contexts. Furthermore, we considered the roles of both the males and the fe- males in the potential food-for-sex exchange. Results indicate that in both species and for both sexes the breeding period promotes decreased aggression. Additionally, females were more per- sistent in their attempts to access the food and were able to monopolize the resource more when in heat as compared to outside the breeding period. Finally, in dogs, but not wolves, females spent more time in proximity to the male＇s bone and had a shorter latency to start eating it when in heat. Overall, this study demonstrates that the food-for-sex hypothesis plays a part in intersexual food sharing in canids, and highlights the role of females in the interaction. These effects were especially the case in dogs, suggesting a potential effect of mating system on food-for-sex responses
基金Supported by The National Basic Research Program (973 Program) ( G1999016003), Graduate Students’ Research Foundation of BeijingForestry University and the Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University
文摘Plant cystatins or phytocystatins are cysteine proteinase inhibitors exist widely in different plant species. Because they can kill insects by inhibiting the digestive function of the cysteine proteinase in gut, they are believed to play an important role in plant’s defense against pests. Phytocystatins contain the conserved QXVXG motif and show some features on their sequence different to animal cystatins. After sequencing the protein directly and the cDNA clone, a large number of plant cystatins have been characterized. A multialignment with BLAST software and a detail analysis of 38 phytocystatins show that phytocystatins possess a specific conserved amino acid sequence [LRVI]-[AGT]-[RQKE]-[FY]- [AS]-[VI]-X-[EGHDQV]-[HYFQ]-N different to the conserved sequence demonstrated by Margis in 1998. This conserved sequence can be enough to detect with exclusivity phytocystatin sequences on protein data banks. A classification of these phytocystatins is performed and they can be divided into 3 groups according to their features on amino acid sequence, and the group-I can be still divided into 3 subgroups based on the feature of their amino acid and genomic sequence. By the CLUSTALX software, the most conserved nucleotide sequences of phytocystatins were found, which could be used to design the degenerate premiers to search new phytocystatins with PCR reaction.
