E. Kejnovsky et al., Localization of male-specifically expressed MROS genes of Silene latifoliaby PCR on flow-sorted sex chromosomes and autosomes, GENETICS, 158(3), 2001, pp. 1269-1277
The dioecious white campion Silene latifolia (syn. Melandrium, album) has h
eteromorphic sex chromosomes, XX in females and XY in males, that are large
r than the autosomes and enable their separation by flow sorting. The group
of MROS genes, the first male-specifically expressed genes in dioecious pl
ants, was recently identified in S. latifolia. To localize the MROS genes,
we used the flow-sorted X chromosomes and autosomes as a template for PCR w
ith internal primers. Our results indicate that the MROS3 gene is located i
n at least two copies tandemly arranged on the X chromosome with additional
copy(ies) on the autosome(s), while MROS1, MROS2, and MROS4 are exclusivel
y autosomal. The specificity of PCR products was checked by digestion with
a restriction enzyme or reamplification using nested primers. Homology sear
ch of databases has shown the presence of five MROS3 homologues in A. thali
ana, four of them arranged in two tandems, each consisting of two copies. W
e conclude that MROS3 is a low-copy gene family, connected with the proper
pollen development, which is present not only in dioecious but also in othe
r dicot plant species.