The highly divergent Jekyll genes,required for sexual reproduction,are lineage specific for the related grass tribes Triticeae and Bromeae

Phylogenetically related groups of species contain lineage‐specific genes that exhibit no sequence similarity to any genes outside the lineage. We describe here that the Jekyll gene, required for sexual reproduction, exists in two much diverged allelic variants, Jek1 and Jek3. Despite low similarity, the Jek1 and Jek3 proteins share identical signal peptides, conserved cysteine positions and direct repeats. The Jek1/Jek3 sequences are located at the same chromosomal locus and inherited in a monogenic Mendelian fashion. Jek3 has a similar expression as Jek1 and complements the Jek1 function in Jek1‐deficient plants. Jek1 and Jek3 allelic variants were almost equally distributed in a collection of 485 wild and domesticated barley accessions. All domesticated barleys harboring the Jek1 allele belong to single haplotype J1‐H1 indicating a genetic bottleneck during domestication. Domesticated barleys harboring the Jek3 allele consisted of three haplotypes. Jekyll‐like sequences were found only in species of the closely related tribes Bromeae and Triticeae but not in other Poaceae. Non‐invasive magnetic resonance imaging revealed intrinsic grain structure in Triticeae and Bromeae, associated with the Jekyll function. The emergence of Jekyll suggests its role in the separation of the Bromeae and Triticeae lineages within the Poaceae and identifies the Jekyll genes as lineage‐specific.     

Synthesis of Y chromosome-specific labeled DNA probes by in vitro DNA amplification

We describe the use of in vitro DNA amplification for production of double-stranded, biotin-labeled DNA probes. Specifically, a 124 BP DNA segment of the Y chromosome-specific 3.4 KB repeat was amplified in preparations of human genomic DNA using the polymerase chain reaction (PCR) and a thermostable DNA polymerase. The PCR products were amplified further in the presence of a molar excess of biotin-11-dUTP. The resulting double-stranded DNA segments showed a high amount of incorporated biotin-11-dUTP. The probes were used in DNA-DNA hybridization experiments without further purification. When DNA sequences flanking the target region are known, probe generation by enzymatic amplification offers a rapid and efficient alternative to molecular cloning and nick translation.     

Isolation and characterization of 12 tetranucleotide repeat microsatellite loci from the green‐backed tit (Parus monticolus)

From a partial genomic library enriched for GATA short tandem repeats, we developed 12 polymorphic microsatellite loci from the green‐backed tit (Parus monticolus). We characterized these loci by genotyping 30 adult individuals with unknown relationship. The number of alleles ranged from four to 17 per locus (mean = 9.3 alleles) and the observed heterozygosity for each locus ranged from 0.633 to 0.933 (mean = 0.789). All loci conformed to Hardy–Weinberg expectations. Four of 66 possible pairwise comparisons between loci showed significant gametic disequilibrium.