Small RNAs are non-coding RNA molecules with 20-30 nucleotides （nt） in length that mainly play regulatory roles in gene expression at the post-transcription level by directly cutting target mRNA or inhibiting its tr...Small RNAs are non-coding RNA molecules with 20-30 nucleotides （nt） in length that mainly play regulatory roles in gene expression at the post-transcription level by directly cutting target mRNA or inhibiting its translation. Small RNAs play regulatory roles in the growth and development process of plants at the core of gene regulatory networks, which has been widely studied and confirmed in sporophyte generation of plants. However, few researches have been conducted on small RNAs and gametophyte generation. It is reported that small RNAs play important roles in floral organ development, gametogenesis, fertilization, and early zygotic development of plants. In addition, various small RNAs also play roles in controlling genetic integrity, cell differentiation and functions during the sexual reproduction process of plants. However, most of the specific functions of small RNAs in the sexual reproduction process are unknown yet. This study mainly aimed to introduce small RNAs in plants, summarize the latest advances in researches of small RNAs and plant sexual reproduction, and make prospect on its future.展开更多
Social conditions experienced prior to sexual maturity influence reproduction later in life in many animals. In simulta- neous hermaphrodites, variation in mating group size influences reproductive investment. As the ...Social conditions experienced prior to sexual maturity influence reproduction later in life in many animals. In simulta- neous hermaphrodites, variation in mating group size influences reproductive investment. As the mating group size increases, re- productive resources devoted to the female function decrease in favor of the male function. Prior to sexual maturity, many her- maphrodites have a protandrous phase during which they produce sperm and can fertilize hermaphrodites＇ eggs. In the simulta- neously hermaphroditic polychaete worm Ophryotrocha diadema, the cost of male reproduction during adolescence is spread over the whole energy budget of worms as shown by a reduced growth rate, a delayed age at sexual maturity and the shortening of life span compared to protandrous males that do not reproduce. Little is known on whether social conditions experienced dur- ing development affect reproductive investment of immature individuals. We investigated whether social conditions affected the length of the protandrous phase, body size and also the subsequent female fecundity of same-age protandrous individuals of O. diadema, which did not had to face competition for egg fertilization. Results show that in large group sizes protandrous males lengthened their protandrous phase, slowed down body growth and decreased their individual investment at the first egg laying compared to protandrous males that were reared in isolation. In the successive egg layings worms adjusted their egg output to the current social conditions. We interpreted these results as an indication that early social conditions represent a social stress result- ing in a reduction of the overall reproductive resources up to the first egg laying .展开更多
基金Supported by National Natural Science Foundation of China(30971986)Specialized Research Fund for the Doctoral Program of Higher Education of China(20110182110013)Doctoral Fund of Southwestern University(SWU111016)~~
文摘Small RNAs are non-coding RNA molecules with 20-30 nucleotides （nt） in length that mainly play regulatory roles in gene expression at the post-transcription level by directly cutting target mRNA or inhibiting its translation. Small RNAs play regulatory roles in the growth and development process of plants at the core of gene regulatory networks, which has been widely studied and confirmed in sporophyte generation of plants. However, few researches have been conducted on small RNAs and gametophyte generation. It is reported that small RNAs play important roles in floral organ development, gametogenesis, fertilization, and early zygotic development of plants. In addition, various small RNAs also play roles in controlling genetic integrity, cell differentiation and functions during the sexual reproduction process of plants. However, most of the specific functions of small RNAs in the sexual reproduction process are unknown yet. This study mainly aimed to introduce small RNAs in plants, summarize the latest advances in researches of small RNAs and plant sexual reproduction, and make prospect on its future.
文摘Social conditions experienced prior to sexual maturity influence reproduction later in life in many animals. In simulta- neous hermaphrodites, variation in mating group size influences reproductive investment. As the mating group size increases, re- productive resources devoted to the female function decrease in favor of the male function. Prior to sexual maturity, many her- maphrodites have a protandrous phase during which they produce sperm and can fertilize hermaphrodites＇ eggs. In the simulta- neously hermaphroditic polychaete worm Ophryotrocha diadema, the cost of male reproduction during adolescence is spread over the whole energy budget of worms as shown by a reduced growth rate, a delayed age at sexual maturity and the shortening of life span compared to protandrous males that do not reproduce. Little is known on whether social conditions experienced dur- ing development affect reproductive investment of immature individuals. We investigated whether social conditions affected the length of the protandrous phase, body size and also the subsequent female fecundity of same-age protandrous individuals of O. diadema, which did not had to face competition for egg fertilization. Results show that in large group sizes protandrous males lengthened their protandrous phase, slowed down body growth and decreased their individual investment at the first egg laying compared to protandrous males that were reared in isolation. In the successive egg layings worms adjusted their egg output to the current social conditions. We interpreted these results as an indication that early social conditions represent a social stress result- ing in a reduction of the overall reproductive resources up to the first egg laying .
