Search tips
Search criteria

Results 1-3 (3)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Comparison of methanogen diversity of yak (Bos grunniens) and cattle (Bos taurus) from the Qinghai-Tibetan plateau, China 
BMC Microbiology  2012;12:237.
Methane emissions by methanogen from livestock ruminants have significantly contributed to the agricultural greenhouse gas effect. It is worthwhile to compare methanogen from “energy-saving” animal (yak) and normal animal (cattle) in order to investigate the link between methanogen structure and low methane production.
Diversity of methanogens from the yak and cattle rumen was investigated by analysis of 16S rRNA gene sequences from rumen digesta samples from four yaks (209 clones) and four cattle (205 clones) from the Qinghai-Tibetan Plateau area (QTP). Overall, a total of 414 clones (i.e. sequences) were examined and assigned to 95 operational taxonomic units (OTUs) using MOTHUR, based upon a 98% species-level identity criterion. Forty-six OTUs were unique to the yak clone library and 34 OTUs were unique to the cattle clone library, while 15 OTUs were found in both libraries. Of the 95 OTUs, 93 putative new species were identified. Sequences belonging to the Thermoplasmatales-affiliated Linage C (TALC) were found to dominate in both libraries, accounting for 80.9% and 62.9% of the sequences from the yak and cattle clone libraries, respectively. Sequences belonging to the Methanobacteriales represented the second largest clade in both libraries. However, Methanobrevibacter wolinii (QTPC 110) was only found in the cattle library. The number of clones from the order Methanomicrobiales was greater in cattle than in the yak clone library. Although the Shannon index value indicated similar diversity between the two libraries, the Libshuff analysis indicated that the methanogen community structure of the yak was significantly different than those from cattle.
This study revealed for the first time the molecular diversity of methanogen community in yaks and cattle in Qinghai-Tibetan Plateau area in China. From the analysis, we conclude that yaks have a unique rumen microbial ecosystem that is significantly different from that of cattle, this may also help to explain why yak produce less methane than cattle.
PMCID: PMC3502369  PMID: 23078429
2.  Characteristics of transgenic tomatoes antisensed for the ethylene receptor genes LeETR1 and LeETR2 *  
Two stable transformed lines containing antisense LeETR1 or LeETR2 sequences and their hybridized line were investigated to determine the effect of LeETR1 and LeETR2 specificity in the ethylene receptor family in tomato (Lycopersicon esculentum Mill.) on ethylene signaling. The transgenic line ale1 containing antisense LeETR1 displayed shorter length of seedling grown in the dark and adult plant in the light, severe epinastic petiole, and accelerated abscission of petiole explant and senescence of flower explant, compared with its wild type B1. The transgenic line ale2 containing antisense LeETR2 also exhibited shorter hypocotyls and slightly accelerated abscission. The phenotypes of cross line dale of LeETR1 and LeETR2 were close to ale1 in many aspects. These results suggested that LeETR1 probably plays a relatively important role in ethylene signaling of tomato growth and development.
PMCID: PMC1500884  PMID: 16773735
Antisense transformation; Ethylene receptor; Ethylene response; Tomato
3.  Characteristics of fruit ripening in tomato mutant epi *  
The characteristics of fruit ripening and expression of ripening-related genes were investigated in epi, an ethylene overproduction mutant of tomato (Lycopersicon esculentum Mill.). The epi produces apparently more ethylene than its wild type VFN8 at every stage of vegetative and fruit growth and ripening; compared to VFN8, the epi fruit showed higher CO2 evolution, faster descending of chlorophyll, slightly quicker increase of carotenoid and lycopene, and faster reduction in pericarp firmness during maturation and ripening; and the mRNAs of three ripening-related genes including E8, pTOM5 and pTOM6 were at higher levels in epi. The ripening-related characteristics changing of the fruit are consistent with the increase of ethylene production and ripening-related genes expression. These results suggest that epi mutation possibly did not affect the ethylene perception and signaling during fruit ripening, and that the modified characteristics of fruit ripening possibly resulted from the ethylene overproduction and increased expression of ripening-related genes.
PMCID: PMC1389880  PMID: 15909334
Epinastic (epi) mutant; Ethylene overproduction; Ethylene signaling; Fruit ripening

Results 1-3 (3)