The maize (Zea mays L.) desynaptic (dy) mutation defines a pathway for meiotic chromosome segregation linking nuclear morphology, telomere distribution, and synapsis.
Murphy SP, Bass HW.AbstractMeiosis involves a dramatic reorganization of the genetic material along with changes in the architecture of nucleoplasm and cytoplasm. In the opisthokonts, nuclear envelope and meiotic chromosome behavior are known to be coordinated by forces generated in the cytoplasm and transferred to the nucleus by the nuclear-envelope protein linkers SUN and KASH. During meiotic prophase I, the telomere bouquet arrangement is known to play roles in interhomolog recognition, pairing, synapsis, interlock resolution, and homologous chromosome recombination. The maize desynaptic (dy) mutant is defective in homologous chromosome synapsis, recombination, telomere-nuclear envelope interactions, and chromosome segregation. A detailed three-dimensional cytological analysis of dy revealed telomere misplacement during the bouquet stage, synaptic irregularities, nuclear envelope distortion, and chromosome bridges at anaphase I. Using linkage and B-A translocation mapping, we placed dy on the long arm of chromosome 3, genetic bin 3.06. SSR marker analysis narrowed the mapping interval to 9 cM. Candidate genes in this region include a PM3-type SUN domain protein, ZmSUN3. No obvious genetic lesions were found in the ZmSUN3 allele of dy, but a conspicuous splice variant, ZmSUN3-sv1, was observed in mRNA from dy. The variant message is predicted to result in the synthesis of a truncated ZmSUN3 protein lacking two C-terminal transmembrane domains. Other potential candidate genes relevant to the documented phenotypes were also considered. In summary, this study reveals that dy causes disruption of a central meiotic pathway connecting nuclear envelope integrity to telomere localization and synapsis during meiotic prophase.
Journal of cell science.J Cell Sci.2012 May 2. [Epub ahead of print]
Meiosis involves a dramatic reorganization of the genetic material along with changes in the architecture of nucleoplasm and cytoplasm. In the opisthokonts, nuclear envelope and meiotic chromosome behavior are known to be coordinated by forces generated in the cytoplasm and transferred to the nucleu
[Expression and inheritance of a desynaptic phenotype with impaired homologous synapsis in rye].
Sosnikhina SP, Mikhaĭlova EI, Tikholiz OA, Tsvetkova NV, Lovtsius AV, Sapronova OS, Fedotova IuS, Kolomiets OL, Bogdanov IuF.AbstractThe cytological phenotype was studied in a desynaptic form isolated from a population of rye cultivar Vyatka. The primary defect of desynaptic plants was identified as nonhomologous (heterologous) chromosome synapsis, which was observed by electron microscopy of synaptonemal complexes (SCs) in meiotic prophase I. Synapsis defects involved switches of synapsing axial elements to nonhomologous partners, asynapsis in the switching region, and foldbacks formed by the SC lateral elements. Defective bivalent formation was observed at later stages: the univalent number varied and multivalent chromosome associations were observed in single cells in metaphase I. The desynaptic phenotype was controlled by two recessive genes, sy8a and sy8b, which acted and were inherited independently. In a hybrid combination with line Ku-2/63, the desynaptic phenotype was suppressed by the dominant allele of a third gene for inhibitor I; the segregation in hybrid families corresponded to 57:7.
Genetika.Genetika.2007 Oct;43(10):1424-33.
The cytological phenotype was studied in a desynaptic form isolated from a population of rye cultivar Vyatka. The primary defect of desynaptic plants was identified as nonhomologous (heterologous) chromosome synapsis, which was observed by electron microscopy of synaptonemal complexes (SCs) in meiot
1 Jan 2003 ... Two are from desyanptic1 (dsy1) pollen mother cells, and three are from desynaptic (dy). ================================================== ========================================= File Name ...