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The density and utility of the molecular genetic linkage map of cultivated sunflower (Helianthus annuus L.) has been greatly increased by the development and mapping of several hundred simple sequence repeat (SSR) markers. Of 1089 public SSR markers described thus far, 408 have been mapped in a recombinant inbred line (RIL) mapping population (RHA280 x RHA801). The goal of the present research was to increase the density of the sunflower map by constructing a new RIL map (PHA x PHB) based on SSRs, adding loci for newly developed SSR markers to the RHA280 x RHA801 RIL map, and integrating the restriction fragment length polymorphism (RFLP) and SSR maps of sunflower. The latter was accomplished by adding 120 SSR marker loci to a backbone of 80 RFLP marker loci on the HA370 x HA372 [F.sub.2] map. The map spanned 1275.4 centimorgans (cM) and had a mean density of 6.3 cM per locus. The PHA x PHB SSR map was constructed from 264 SSR marker loci, spanned 1199.4 cM, and had a mean density of 4.5 cM per locus. The RHA280 x RHA801 map was constructed by adding 118 new SSR and insertion-deletion (INDEL) marker loci to 459 previously mapped SSR marker loci. The 577-locus map spanned 1423.0 cM and bad a mean density of 2.5 cM per locus. The three maps were constructed from 1044 DNA marker loci (701 unique SSR and 89 unique RFLP or INDEL marker loci) and supply a dense genomewide framework of sequence-based DNA markers for molecular breeding and genomics research in sunflower., THE FIRST MOLECULAR GENETIC LINKAGE MAPS Of cultivated sunflower were developed by means of RFLP (Berry et al., 1995, 1996, 1997; Gentzbittel et al., 1995, 1999; Jan et al., 1998) [...]

Genes responsible for human-specific phenotypes may have been under altered selective pressures in human evolution and thus exhibit changes in substitution rate and pattern at the protein sequence level. Using comparative analysis of human, chimpanzee, and mouse protein sequences, we identified two genes (PRM2 and FOXP2) with significantly enhanced evolutionary rates in the hominid lineage. PRM2 is a histone-like protein essential to spermatogenesis and was previously reported to be a likely target of sexual selection in humans and chimpanzees. FOXP2 is a transcription factor involved in speech and language development. Human FOXP2 experienced a >60-fold increase in substitution rate and incorporated two fixed amino acid changes in a broadly defined transcription suppression domain. A survey of a diverse group of placental mammals reveals the uniqueness of the human FOXP2 sequence and a population genetic analysis indicates possible adaptive selection behind the accelerated evolution. Taken together, our results suggest an important role that FOXP2 may have played in the origin of human speech and demonstrate a strategy for identifying candidate genes underlying the emergences of human-specific features.

Genetic marker systems have improved dramatically in the past 10 yr. Each new system needs to be evaluated for its distribution of markers on genetic linkage maps to validate its use for genetic analysis. The resulting maps an also useful for establishing the genetic positions of genes affecting important phenotypes. We have constructed a high density map in soybean [Glycine max (L.) Merr.] using a 300 RIL (recombinant inbred line) population from BSR101 x PI437.654 by first constructing an RFLP (restriction fragment length polymorphism) 'scaffold' map based on the entire population. The RFLP anchored map was then further populated with AFLP (amplified fragment length polymorphism) markers based on only a 42 RIL subset. We report here an 840 marker map consisting of 165 RFLP, 25 RAPD (random amplified polymorphic DNA), and 650 AFLP markers spread over 29 linkage groups representing 3441 cM distance. Although clustering of AFLP markers occurred, markers were mapped to every linkage group and were well distributed relative to other marker systems. The AFLP marker system appears to be a useful approach for generating high density genetic maps in soybean., GENETIC MAPPING has been greatly enhanced in the last decade with the introduction of novel genetic marker systems. These systems have resulted in increased capabilities for detecting DNA polymorphism and [...]

Pheromones are water-soluble chemicals released and sensed by individuals of the same species to elicit social and reproductive behaviors or physiological changes; they are perceived primarily by the vomeronasal organ (VNO) in terrestrial vertebrates. Humans and some related primates possess only vestigial VNOs and have no or significantly reduced ability to detect pheromones, a phenomenon not well understood at the molecular level. Here we show that genes encoding the TRP2 ion channel and V1R pheromone receptors, two components of the vomeronasal pheromone signal transduction pathway, have been impaired and removed from functional constraints since shortly before the separation of hominoids and Old World monkeys ≈23 million years ago, and that the random inactivation of pheromone receptor genes is an ongoing process even in present-day humans. The phylogenetic distribution of vomeronasal pheromone insensitivity is concordant with those of conspicuous female sexual swelling and male trichromatic color vision, suggesting that a vision-based signaling-sensory mechanism may have in part replaced the VNO-mediated chemical-based system in the social/reproductive activities of hominoids and Old World monkeys (catarrhines). [ABSTRACT FROM AUTHOR]

The density and utility of the molecular genetic linkage map of cultivated sunflower (Helianthus annuus L.) has been greatly increased by the development and mapping of several hundred simple sequence repeat (SSR) markers. Of 1089 public SSR markers described thus far, 408 have been mapped in a recombinant inbred line (RIL) mapping population (RHA280 × RHA801). The goal of the present research was to increase the density of the sunflower map by constructing a new RIL map (PHA × PHB) based on SSRs, adding loci for newly developed SSR markers to the RHA280 x RHA801 RIL map, and integrating the restriction fragment length polymorphism (RFLP) and SSR maps of sunflower. The latter was accomplished by adding 120 SSR marker loci to a backbone of 80 RFLP marker loci on the HA370 × HA372 F[sub 2] map. The map spanned 1275.4 centimorgans (cM) and had a mean density of 6.3 cM per locus. The PHA × PHB SSR map was constructed from 264 SSR marker loci, spanned 1199.4 cM, and had a mean density of 4.5 cM per locus. The RHA280 × RHA801 map was constructed by adding 118 new SSR and insertion-deletion (INDEL) marker loci to 459 previously mapped SSR marker loci. The 577-locus map spanned 1423.0 cM and had a mean density of 2.5 cM per locus. The three maps were constructed from 1044 DNA marker loci (701 unique SSR and 89 unique RFLP or INDEL marker loci) and supply a dense genomewide framework of sequence-based DNA markers for molecular breeding and genomics research in sunflower. [ABSTRACT FROM AUTHOR]

Identifies two genes (PRM2 and FOXP2) with significantly enhanced evolutionary rates in the hominid lineage, using comparative analysis of human, chimpanzee, and mouse protein sequences. PRM2 is a histone-like protein essential to spermatogenesis and was previously reported to be a likely target of sexual selection in humans and chimpanzees. FOXP2 is a transcription factor involved in speech and language development. Human FOXP2 experienced a >60-fold increase in substitution rate and incorporated two fixed amino acid changes in a broadly defined transcription suppression domain. A survey of a diverse group of placental mammals reveals the uniqueness of the human FOXP2 sequence and a population genetic analysis indicates possible adaptive selection behind the accelerated evolution. Taken together, our results suggest an important role that FOXP2 may have played in the origin of human speech and demonstrate a strategy for identifying candidate genes underlying the emergences of human-specific features.