1
$\begingroup$

I've been told some interesting facts about oenothera. Apparently in this species some lineages have been through some translocations and in results to these translocations and in consequence, some chromosomes are inherited exclusively through the female function while some other chromosomes are inherited only through the male function.

Can you please provide a summary description of how things work in this species concerning the meiosis, the haplo-diplontic life cycle and the recombination?

$\endgroup$
1
$\begingroup$

I would recommend looking at this paper, and in particular the section "A SHORT INTRODUCTION TO OENOTHERA GENETICS":

The genetics of Oenothera is a genetics of entire haploid genomes (Renner complexes), which inherit as single units and are entitled with names such as hjohansen, Galbicans, or Gflavens (for terminology, see materials and methods). All loci of a Renner complex are in linkage disequilibrium.

Figure 1 from that paper shows what that looks like in meiosis, in terms of its impact on chromosome pairing- basically chromosome pairing forms rings of chromosomes linked by translocations.

enter image description here

Figure 1.

Additionally, it appears that plastid inheritance is biparental to some extent. These also contain pollen-lethal factors related to autosomes, such that cytonuclear incompatibilities kill pollen recombinants between a Renner complex and plastids (eggs are unaffected, Figure 2, 3):

Consequently, the F1 generation is identical to the parental generation without segregation of traits, since chromosomes separate as a set without intermixing.

The set of plastids ("plastome") will then break down in the F2 such that assortment can happen.

Selfing of appropriate flowers ensures that only plastome I is inherited to the next generation. However, in F2 the nuclear genome splits into the progenies CC-I and AC-I...

Since the ring of 14 chromosomes should inhibit free segregation of individual chromosomes and practically homologous recombination between haploid genomes in the hybrid AC, the coding potential of the A and C genomes is not mixed and a seemingly unchanged, homozygous CC genotype, now associated with plastome I, occurs in F2.

enter image description here

Figure 2.

enter image description here

Figure 3.

So it's rather complex. Hopefully that sheds some light on it, but it's understandable if it's still confusing!

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.