A unisexual species is generally associated with polyploidy, and reproduced by a unisexual reproduction mode, such as gyno- genesis, hybridogenesis or parthenogenesis. Compared with other unisexual and polyploid speci...A unisexual species is generally associated with polyploidy, and reproduced by a unisexual reproduction mode, such as gyno- genesis, hybridogenesis or parthenogenesis. Compared with other unisexual and polyploid species, gibel carp (Carassius au- ratus gibelio) has a higher ploidy level of hexaploid. It has undergone several successive rounds of genome polyploidy, and experienced an additional, more recent genome duplication event. More significantly, the dual reproduction modes, including gynogenesis and sexual reproduction, have been demonstrated to coexist in the polyploid gibel carp. This article reviews the genetic basis concerning polyploidy origin, clonal diversity and dual reproduction modes, and outlines the progress in new va- riety breeding and gene identification involved in the reproduction and early development. The data suggests that gibel carp are under an evolutionary trajectory of diploidization. As a novel evolutionary developmental (Evo-Devo) biology model, this work highlights future perspectives about the functional divergence of duplicated genes and the sexual origin of vertebrate animals.展开更多
Unisexual reproduction is generally relevant to polyploidy, and unisexual vertebrates are often considered an evolutionary “dead end” due to the accumulation of deleterious mutations and absence of genetic diversity...Unisexual reproduction is generally relevant to polyploidy, and unisexual vertebrates are often considered an evolutionary “dead end” due to the accumulation of deleterious mutations and absence of genetic diversity. However, some unisexual polyploids have developed strategies to avoid genomic decay, and thus provide ideal models to unveil unexplored evolutionary mechanisms, from the reproductive success to clonal diversity creation. This article reviews the evolutionary mechanisms for overcoming meiotic barrier and generating genetic diversity in unisexual vertebrates, and summarizes recent research advancements in the polyploid Carassius complex. Gynogenetic gibel carp(Carassius gibelio) is a unique amphitriploid that has undergone a recurrent autotriploidy and has overcome the bottleneck of triploid sterility via gynogenesis. Recently, an efficient strategy in which ploidy changes, including from amphitriploid to amphitetraploid, then from amphitetraploid to novel amphitriploid, drive unisexual-sexual-unisexual reproduction transition and clonal diversity has been revealed.Based on this new discovery, multigenomic reconstruction biotechnology has been used to breed a novel strain with superior growth and stronger disease resistance. Moreover, a unique reproduction mode that combines both abilities of ameiotic oogenesis and sperm-egg fusion,termed as ameio-fusiongensis, has been discovered, and it provides an efficient approach to synthesize sterile allopolyploids. In order to avoid ecological risks upon escape and protect the sustainable property rights of the aquaculture seed industry, a controllable fertility biotechnology approach for precise breeding is being developed by integrating sterile allopolyploid synthesis and gene-editing techniques.This review provides novel insights into the origin and evolution of unisexual vertebrates and into the attempts being made to exploit new breeding biotechnologies in aquaculture.展开更多
Figured black walnut lumber is a specialty wood product that commands a high price for manufacturing fine furniture and interior paneling. Two common figured grain patterns occur in walnut;they are known as “fiddle-b...Figured black walnut lumber is a specialty wood product that commands a high price for manufacturing fine furniture and interior paneling. Two common figured grain patterns occur in walnut;they are known as “fiddle-back” or “curly” grain, depending on the number of horizontal lines visible in the grain of the finished wood. The occurrence of figured walnut in nature is rare and unpredictable. Trees that have consistent figured patterns throughout the log are of exceptional value. Conversely, trees with partial or spotty figured patterns are considered defective and are reduced in value. Conventional breeding of seedlings, or cloning figured trees by grafting, are possible methods to propagate figured wood in walnut. The value of such material, however, will depend on figure being expressed predictably. For breeding to succeed, the trait of interest must be genetic and heritable. For clonal propagation to be effective, the trait must be reproduced true-to-type. In this study, we evaluate the grain pattern of both grafted and seedling walnut from several highly figured wild selections. Logs from grafted trees of three clones propagated in the 1970s in Kansas were evaluated. Only one log from one clone showed some figure in its lumber. Ten-year-old seedlings from the figured walnut clone “Lamb” were grown and cut in Indiana and evaluated for figured grain, and none showed any sign of figured grain developing. Our conclusion is that figured grain in black walnut does not propagate true-to-type through grafting or by growing open-pollinated seed. Although evidence of some genetic control of figure was found, environmental and other factors appear to play a greater role.展开更多
The major goal for long-term poplar breeding can be formulated as maximizing annual progress in Group Merit Gain at a given annual budget （GMG/Y＊）. To evaluate different breeding scenarios, a deterministic simulato...The major goal for long-term poplar breeding can be formulated as maximizing annual progress in Group Merit Gain at a given annual budget （GMG/Y＊）. To evaluate different breeding scenarios, a deterministic simulator BREEDING CYCLE ANALYZER covering the most important aspects （gain, cost, time, technique, and gene diversity） of a full breeding cycle was used. The breeding strategies considered was based on pairwise crossing of the selected breeding population and balanced within family selection for the next breeding population. A main scenario and a number of alternative scenarios within these constraints were evaluated using estimates of the best available inputs for poplars. In focus was a comparison between three different testing scenarios for selecting the parents mated to create future breeding generations, thus selecting based on phenotype, clone test or progeny test. For the main scenario, the highest GMG/Y, and the optimal selection age for clone, phenotype and progeny strategies were 0.7480 %, 0.6989% and 0.4675%; 7, 6, and 11 years respectively. Clone test was best except when heritability was high, plant price was high or total budget was low; phenotype strategy was the second except for the case of extremely low narrow-sense heritability, for which the progeny strategy was a little more efficient than phenotype strategy. GMG/Y was markedly affected by narrow-sense heritability, additive variance at mature age, rotation age, plant-dependent cost, total budget and the time needed to produce the test plants, while diversity loss and recombination cost had rather weak effect on GMG/Y. Short rotation age and cheap testing cost favoured all three testing strategies. Comparably short rotation age, low plant-dependent cost and high total budget seem to promote early selection for progeny strategy.展开更多
基金supported by the National Key Basic Research Program (Grant No. 2010CB126301)the National Natural Science Foundation of China (Grant No. 30630050)+1 种基金the Open Project of State Key Laboratory of Freshwater Ecology and Biotechnology (Grant No. 2008FB007)the Innovation Project of Institute of Hydrobiology, Chinese Academy of Sciences (Grant No. 075A01)
文摘A unisexual species is generally associated with polyploidy, and reproduced by a unisexual reproduction mode, such as gyno- genesis, hybridogenesis or parthenogenesis. Compared with other unisexual and polyploid species, gibel carp (Carassius au- ratus gibelio) has a higher ploidy level of hexaploid. It has undergone several successive rounds of genome polyploidy, and experienced an additional, more recent genome duplication event. More significantly, the dual reproduction modes, including gynogenesis and sexual reproduction, have been demonstrated to coexist in the polyploid gibel carp. This article reviews the genetic basis concerning polyploidy origin, clonal diversity and dual reproduction modes, and outlines the progress in new va- riety breeding and gene identification involved in the reproduction and early development. The data suggests that gibel carp are under an evolutionary trajectory of diploidization. As a novel evolutionary developmental (Evo-Devo) biology model, this work highlights future perspectives about the functional divergence of duplicated genes and the sexual origin of vertebrate animals.
基金supported by“Agricultural Biological Breeding-2030”major project(2023ZD0405504)the National Natural Science Foundation of China(31930111 and 32102785)+5 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDA024030104)the China Agriculture Research System of MOF and MARA(CARS-45-07)Science and Technology Major Project of Hubei Province(2023BBA001)Hubei Hongshan Laboratory(2021hszd001)Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)the Excellent Young Talents program of Wuhan。
文摘Unisexual reproduction is generally relevant to polyploidy, and unisexual vertebrates are often considered an evolutionary “dead end” due to the accumulation of deleterious mutations and absence of genetic diversity. However, some unisexual polyploids have developed strategies to avoid genomic decay, and thus provide ideal models to unveil unexplored evolutionary mechanisms, from the reproductive success to clonal diversity creation. This article reviews the evolutionary mechanisms for overcoming meiotic barrier and generating genetic diversity in unisexual vertebrates, and summarizes recent research advancements in the polyploid Carassius complex. Gynogenetic gibel carp(Carassius gibelio) is a unique amphitriploid that has undergone a recurrent autotriploidy and has overcome the bottleneck of triploid sterility via gynogenesis. Recently, an efficient strategy in which ploidy changes, including from amphitriploid to amphitetraploid, then from amphitetraploid to novel amphitriploid, drive unisexual-sexual-unisexual reproduction transition and clonal diversity has been revealed.Based on this new discovery, multigenomic reconstruction biotechnology has been used to breed a novel strain with superior growth and stronger disease resistance. Moreover, a unique reproduction mode that combines both abilities of ameiotic oogenesis and sperm-egg fusion,termed as ameio-fusiongensis, has been discovered, and it provides an efficient approach to synthesize sterile allopolyploids. In order to avoid ecological risks upon escape and protect the sustainable property rights of the aquaculture seed industry, a controllable fertility biotechnology approach for precise breeding is being developed by integrating sterile allopolyploid synthesis and gene-editing techniques.This review provides novel insights into the origin and evolution of unisexual vertebrates and into the attempts being made to exploit new breeding biotechnologies in aquaculture.
文摘Figured black walnut lumber is a specialty wood product that commands a high price for manufacturing fine furniture and interior paneling. Two common figured grain patterns occur in walnut;they are known as “fiddle-back” or “curly” grain, depending on the number of horizontal lines visible in the grain of the finished wood. The occurrence of figured walnut in nature is rare and unpredictable. Trees that have consistent figured patterns throughout the log are of exceptional value. Conversely, trees with partial or spotty figured patterns are considered defective and are reduced in value. Conventional breeding of seedlings, or cloning figured trees by grafting, are possible methods to propagate figured wood in walnut. The value of such material, however, will depend on figure being expressed predictably. For breeding to succeed, the trait of interest must be genetic and heritable. For clonal propagation to be effective, the trait must be reproduced true-to-type. In this study, we evaluate the grain pattern of both grafted and seedling walnut from several highly figured wild selections. Logs from grafted trees of three clones propagated in the 1970s in Kansas were evaluated. Only one log from one clone showed some figure in its lumber. Ten-year-old seedlings from the figured walnut clone “Lamb” were grown and cut in Indiana and evaluated for figured grain, and none showed any sign of figured grain developing. Our conclusion is that figured grain in black walnut does not propagate true-to-type through grafting or by growing open-pollinated seed. Although evidence of some genetic control of figure was found, environmental and other factors appear to play a greater role.
基金This study was supported by Kempe Foundation, the ChinaScholarship Council (CSC) and Jiangsu Hi-tech foundation (BG2003306)
文摘The major goal for long-term poplar breeding can be formulated as maximizing annual progress in Group Merit Gain at a given annual budget （GMG/Y＊）. To evaluate different breeding scenarios, a deterministic simulator BREEDING CYCLE ANALYZER covering the most important aspects （gain, cost, time, technique, and gene diversity） of a full breeding cycle was used. The breeding strategies considered was based on pairwise crossing of the selected breeding population and balanced within family selection for the next breeding population. A main scenario and a number of alternative scenarios within these constraints were evaluated using estimates of the best available inputs for poplars. In focus was a comparison between three different testing scenarios for selecting the parents mated to create future breeding generations, thus selecting based on phenotype, clone test or progeny test. For the main scenario, the highest GMG/Y, and the optimal selection age for clone, phenotype and progeny strategies were 0.7480 %, 0.6989% and 0.4675%; 7, 6, and 11 years respectively. Clone test was best except when heritability was high, plant price was high or total budget was low; phenotype strategy was the second except for the case of extremely low narrow-sense heritability, for which the progeny strategy was a little more efficient than phenotype strategy. GMG/Y was markedly affected by narrow-sense heritability, additive variance at mature age, rotation age, plant-dependent cost, total budget and the time needed to produce the test plants, while diversity loss and recombination cost had rather weak effect on GMG/Y. Short rotation age and cheap testing cost favoured all three testing strategies. Comparably short rotation age, low plant-dependent cost and high total budget seem to promote early selection for progeny strategy.
