Genetic Analysis and Molecular Mapping of a Male Sterile Mutant in Rice

Abstract The Drosophila gene exuperantia (exu) is a maternal effect gene which is needed for proper localization of the bcd RNA during the formation of oocytes. We have extended the characterization of the exu phenotype and find that the gene functions in the male as well as the female germline. Six of seven exu alleles are male-sterile; mutant defects in spermatogenesis first appear during meiosis. A genetic analysis presented here shows that the exu gene does not encode a zygotic vital function. The isolation of two overlapping deficiencies that delete exu function localizes the gene cytologically to polytene bands 57A4-B1. We describe the molecular cloning and identification of the gene, and show that it encodes overlapping sex-specific transcripts of 2.9 kb in the male and 2.1 kb in the female. We also show that these two transcripts are limited in expression to the germline. We demonstrate that one allele, exuVL57, is a deletion of about 700 bp which results in a loss of both transcripts.

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Genetic analysis and mapping of a thermosensitive genic male sterility gene, tms6(t), in rice (Oryza sativa L.)

Genome ◽

10.1139/g09-092 ◽

2010 ◽

Vol 53 (2) ◽

pp. 119-124 ◽

Cited By ~ 7

Author(s):

Xia Liu ◽

Xihong Li ◽

Xin Zhang ◽

Songwen Wang

Keyword(s):

Genetic Analysis ◽

Molecular Mapping ◽

Oryza Sativa L ◽

Bulked Segregant Analysis ◽

Recessive Gene ◽

Male Sterile ◽

Chromosome 10 ◽

Physical Maps ◽

Specific Temperature ◽

Simple Sequence

Thermosensitive genic male-sterile (TGMS) rice is widely used in hybrid rice production. Because of its specific temperature requirement, it can be used only in a narrow rice-growing zone in Asia. A newly discovered TGMS line, G20S, has an opposite phenotype compared with normal TGMS lines. G20S is completely sterile when the temperature is lower than 29.5 °C. Thus, it can be widely used in a larger area. Genetic analysis indicated that the sterility of G20S was controlled by a single recessive gene that was named tms6(t). An F2 population from the cross between G20S and Jing226 was developed and used for molecular mapping of the tms6(t) gene. The simple sequence repeat technique, combined with bulked segregant analysis, was used to screen markers linked to the target gene, and linkage markers such as RM216, RM2504, RM3152, and RM4455 were identified. These markers are all located on chromosome 10; therefore, tms6(t) was subsequently mapped on chromosome 10. Co-segregation analysis using the F2 population showed that two of these markers, RM3152 and RM4455, were closely linked to tms6(t) at distances of 3.00 cM and 1.10 cM, respectively. Additionally, integration of the genetic and physical maps showed that there were 15 BAC/PAC clones overlapping between RM3152 and RM4455, and tms6(t) was mapped to an interval of 1455 kb.

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Phenotypic characterization, genetic analysis, and molecular mapping of a new mutant gene for male sterility in rice

Genome ◽

10.1139/g08-009 ◽

2008 ◽

Vol 51 (4) ◽

pp. 303-308 ◽

Cited By ~ 6

Author(s):

Ling Zuo ◽

Shuangcheng Li ◽

Mingguang Chu ◽

Shiquan Wang ◽

Qiming Deng ◽

...

Keyword(s):

Genetic Analysis ◽

Molecular Mapping ◽

Spontaneous Mutation ◽

Recessive Gene ◽

Pollen Grains ◽

Mutant Gene ◽

Phenotypic Characterization ◽

Chromosome 4 ◽

Male Sterile ◽

Rice Mutant

xs1 is a male-sterile rice mutant derived from a spontaneous mutation. The floret of the mutant, consisting of 6 stamens and 1 pistil, looks the same as that of the wild type except that the filaments are long and thin and the anthers are withered in white transparence. It is confirmed that xs1 is a no-pollen type of male-sterile mutant, for no pollen grains can be stained with I2–KI solution and the anther locules are always hollow. Anther transverse sections indicate that the mutant microspores are abnormally condensed and agglomerated to form a deeply stained cluster at the late microspore stage, which results in cessation of the vacuolation process of microspores, and, therefore, the mutant forms no functional pollens for reproduction. Genetic analysis of 4 F2 populations and 3 BC1F1 populations revealed that the mutation is controlled by a single recessive gene, termed VR1 (Vacuolation retardation 1). Screening of 432 F2 mutant individuals derived from the cross of xs1 × G603 with simple sequence repeat markers revealed that VR1 is located between the molecular markers RM17411 and RM5030, at distances of 0.7 and 1.5 cM, respectively, on chromosome 4. VR1 is a new male fertility controlling gene located on chromosome 4 in rice.

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