Development Of Female Reproductive Organs Research Articles

Analysis of gymnosperm two-AP2-domain-containing genes.

AINTEGUMENTA (ANT) and APETALA2 (AP2) are transcription factors that are involved in several developmental processes in Arabidopsis thaliana. They are similar in structure, containing two AP2 domains, and have partially redundant functions in reproductive organ development. Expression and functional analyses of ANT and AP2 homologs have been performed previously in almost all angiosperms. In this study, one ANT homolog and two AP2 homologs were isolated from the gymnosperm Pinus thunbergii and were named PtANTL1, PtAP2L1, and PtAP2L2. PtANTL1 is the first reported gymnosperm ANT homologous gene. Based on a gene tree constructed with sequences of all A. thaliana two-AP2-domain-containing genes, it is likely that PtANTL1 and ANT, and likewise PtAP2L1 and AP2, are orthologs. The expression patterns of PtANTL1/PtAP2L1/PtAP2L2 were examined with Southern hybridization of the quantitative RT-PCR products and in situ hybridization. PtANTL1 and PtAP2L1 had almost identical expression patterns in the analyzed organs, and PtANTL1/PtAP2L1/PtAP2L2 were continually expressed in the developing female cone. Our analysis suggests that gymnosperms have orthologs to both ANT and AP2, and that the most recent common ancestor of extant seed plants has two type AP2 subfamily genes, ANT-like and AP2-like, involved in the development of female reproductive organs.

Genetic engineering of reproductive incompetence in radiata pine

An important application of genetic engineering to commercial forestry is the generation of reproductively incompetent trees. This requires isolation and characterisation of the regulatory regions of the genes expressed at the different stages of male and female reproductive-organ development. A gene family showing specific expression inPinus radiata immature male and female cone buds has been isolated and characterised. We discuss different strategies for genetic engineering of reproductive incompetence, concentrating on cell ablation and the problems and possible solutions associated with this approach.

GENETIC ENGINEERING OF REPRODUCTIVE STERILITY IN PINUS RADIATA

Generation of transgenic trees for reproductive incompetence is an important application of genetic engineering to commercial forestry. This involves isolation and characterisation of the regulatory regions of the genes expressed at the very early stages of male and female reproductive organ development. A gene family showing specific expression in Pinus radiata immature male and female cone-buds was isolated and characterised. A cell ablation strategy involving expression of toxin genes, under the control of the regulatory sequences of these genes, led to the ablation of the target cells. The major problem with this strategy was 'promoter leakage', low (background) levels of expression of some flower-specific promoters in vegetative tissues during flowering and non-flowering periods. To improve the cell ablation strategy, a cascade of chimeric genes was designed. During non-flowering, controlled expression of the anti-toxin gene from Bacillus amyloliquefaciens, Barstar, in non-flowering tissues arrested the accumulation of the toxic Barnase protein.

Diversification of C-function activity in maize flower development.

The Arabidopsis gene AGAMOUS is required for male and female reproductive organ development and for floral determinacy. Reverse genetics allowed the isolation of a transposon-induced mutation in ZAG1, the maize homolog of AGAMOUS. ZAG1 mutants exhibited a loss of determinacy, but the identity of reproductive organs was largely unaffected. This suggested a redundancy in maize sex organ specification that led to the identification and cloning of a second AGAMOUS homolog, ZMM2, that has a pattern of expression distinct from that of ZAG1. C-function organ identity in maize (as defined by the A, B, C model of floral organ development) may therefore be orchestrated by two closely related genes, ZAG1 and ZMM2, with overlapping but nonidentical activities.

雌スルメイカの成熟にともなう卵巣および付属生殖器官の発達について

雌スルメイカの成熟にともなう卵巣および付属生殖器官の発達について

Development of female reproductive organs of ducks

Development of female reproductive organs of ducks