Score: 4.00 |
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| Title: A germ cell specific gene of the ARGONAUTE family is essential for the progression of premeiotic mitosis and meiosis during sporogenesis in rice .
| | Author: Nonomura K Morohoshi A Nakano M Eiguchi M Miyao A Hirochika H Kurata N | | Journal: Plant Cell Citation: V : 19 P : 2583-94 Year: 2007 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub17675402 Accession (PMID): 17675402 | | Abstract: The rice ( Oryza sativa ) genome contains 18 copies of genes of the ARGONAUTE ( AGO ) family .
Although AGO members play important roles in RNA-mediated silencing during plant development , a family member that is specifically involved in sexual reproduction has not been identified in plants .
We identified the rice AGO gene MEIOSIS ARRESTED AT LEPTOTENE1 ( MEL1 ) from the analysis of seed-sterile mutants .
In the mel1 mutant , chromosome condensation was arrested at early meiotic stages and irregularly sized , multinucleated , and vacuolated pollen mother cells ( PMCs ) frequently appeared in developing anthers .
In addition , histone H3 lysine-9 dimethylation of pericentromeres was rarely reduced and modification of the nucleolar-organizing region was altered in mel1 mutant PMCs .
The mutation also affected female germ cell development .
These results indicate that the germ cell-specific rice MEL1 gene regulates the cell division of premeiotic germ cells , the proper modification of meiotic chromosomes , and the faithful progression of meiosis , probably via small RNA-mediated gene silencing , but not the initiation and establishment of germ cells themselves .
| Matching Sentences:
[ Sen. 3, subscore: 1.00 ]: We identified the rice AGO gene MEIOSIS ARRESTED AT LEPTOTENE1 ( MEL1 ) from the analysis of seed-sterile mutants .
[ Sen. 4, subscore: 1.00 ]: In the mel1 mutant , chromosome condensation was arrested at early meiotic stages and irregularly sized , multinucleated , and vacuolated pollen mother cells ( PMCs ) frequently appeared in developing anthers .
[ Sen. 5, subscore: 1.00 ]: In addition , histone H3 lysine-9 dimethylation of pericentromeres was rarely reduced and modification of the nucleolar-organizing region was altered in mel1 mutant PMCs .
[ Sen. 7, subscore: 1.00 ]: These results indicate that the germ cell-specific rice MEL1 gene regulates the cell division of premeiotic germ cells , the proper modification of meiotic chromosomes , and the faithful progression of meiosis , probably via small RNA-mediated gene silencing , but not the initiation and establishment of germ cells themselves .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 2.00 |
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| Title: The rice gene DEFECTIVE TAPETUM AND MEIOCYTES 1 ( DTM1 ) is required for early tapetum development and meiosis .
| | Author: Yi J Kim SR Lee DY Moon S Lee YS Jung KH Hwang I An G | | Journal: Plant J Citation: V : 70 P : 256-70 Year: 2012 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub22111585 Accession (PMID): 22111585 | | Abstract: Tapetum development and meiosis play crucial roles in anther development .
Here we identified a rice gene , DEFECTIVE TAPETUM AND MEIOCYTES 1 ( DTM1 ) , which controls the early stages of that development .
This gene encodes for an endoplasmic reticulum ( ER ) membrane protein that is present only in cereals .
Our T-DNA insertion mutations gave rise to abnormal tapetal formation .
Cellular organelles , especially the ER , were underdeveloped , which led to hampered differentiation and degeneration of the tapetum .
In addition , the development of pollen mother cells was arrested at the early stages of meiotic prophase I RNA in-situ hybridization analyses showed that DTM1 transcripts were most abundant in tapetal cells at stages 6 and 7 , and moderately in the pollen mother cells and meiocytes .
Transcripts of UDT1 , which functions in tapetum development during early meiosis , were reduced in dtm1 anthers , as were those of PAIR1 , which is involved in chromosome pairing and synapsis during meiosis .
However , expression of MSP1 and MEL1 , which function in anther wall specification and germ cell division , respectively , was not altered in the dtm1 mutant .
Moreover , transcripts of DTM1 were reduced in msp1 mutant anthers , but not in udt1 and pair1 mutants .
These results , together with their mutant phenotypes , suggest that DTM1 plays important roles in the ER membrane during early tapetum development , functioning after MSP1 and before UDT1 , and also in meiocyte development , after MEL1 and before PAIR1 .
| Matching Sentences:
[ Sen. 8, subscore: 1.00 ]: However , expression of MSP1 and MEL1 , which function in anther wall specification and germ cell division , respectively , was not altered in the dtm1 mutant .
[ Sen. 10, subscore: 1.00 ]: These results , together with their mutant phenotypes , suggest that DTM1 plays important roles in the ER membrane during early tapetum development , functioning after MSP1 and before UDT1 , and also in meiocyte development , after MEL1 and before PAIR1 .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
