Mitochondrial DNA rearrangements in Pennisetum associated with reversion from cytoplasmic male sterility to fertility

Abstract

Endonuclease restriction fragment patterns of Pennisetum americanum L. mitochondrial DNAs (mtDNAs) from a cytoplasmic male-sterile (CMS-A1), fertile revertants and a normal fertile cytoplasm were variable, while chloroplast DNA from those lines lacked variation. Comparisons between mtDNAs of CMS-A1 (parental) and fertile revertant lines revealed the presence of a unique 4.7 kbp PstI fragment in the sterile line that was not detected in any of the revertant lines. A 9.7 kbp PstI fragment was found in all of the revertants, but not in the CMS-A1. Neither of those fragments was found in the normal cytoplasm mtDNA. Hybridization studies revealed two sets of multiple homologies: 1) the 4.7 kbp fragment had homology with a 10.9 kbp and a 13.6 kbp fragment; and 2) the 9.7 kbp fragment was homologous with the 13.6 kbp fragment. The presence of those two repeated mitochondrial sequences on the altered fragments suggests that they may be involved in the recombinational associated events with reversion from CMS to fertility in P. americanum.

MutS HOMOLOG1 silencing mediatesORF220substoichiometric shifting and causes male sterility inBrassica juncea

“…Mitochondrial DNA rearrangements are often observed in some CMS systems upon reversion to fertility ( Fauron et al , 1987 ; Smith et al , 1987 ; Escotecarlson et al , 1988 ; Mackenzie et al , 1988 ; Bellaoui et al , 1998 ; Janska et al , 1998 ), with dramatic reduction in relative copy number of the CMS sequence in each case. Here, we demonstrated that the SSS of CMS-associated ORF220 occurs in association with fertility reversion in CMS B. juncea .…”

Construction of BAC libraries from two apomictic grasses to study the microcolinearity of their apospory-specific genomic regions

“…To estimate the representation of cpDNA in both libraries we hybridized one high-density filter from each library (18,432 clones) with a 1,900-bp fragment amplified between the trnH and trnK primers (Demesure et al 1995). Correcting for the insert size of the libraries and for an approximate chloroplast genome size in P. glaucum of 120 kb (Smith et al 1987), an estimated 0.1% and 0.7% of clones are of chloroplast origin in the polyhaploid and buffelgrass libraries, respectively. The proportion of mitochondrial clones were estimated at 0.2% and 0.5% in polyhaploid and buffelgrass libraries, respectively.…”

Cytoplasmic-nuclear male sterility in pearl millet: comparative RFLP and transcript analyses of isonuclear male-sterile lines

“…No transcript variation was observed either in the leaves or spikelets or upon restoration of A and A cytoplasms (HA and HA ). Smith et al (1987) reported identifying and cloning fragments that were rearranged upon reversion of the A CMS cytoplasm to fertility. Four PstI fragments were cloned: a 4.7 kbp fragment found only in the A CMS line, a 9.7 kbp fragment found in 81B and in eight fertile revertants of the A cytoplasm, a 13.6 kbp fragment found in 81A , 81B and one revertant and a 10.9 kbp fragment found in all cytoplasms.…”