@article {69284, title = {Analysis of meiotic recombination in Drosophila simulans shows heterozygous inversions do not cause an interchromosomal effect}, journal = {Genetics}, year = {2024}, month = {2024 May 19}, abstract = {

Chromosome inversions are of unique importance in the evolution of genomes and species because when heterozygous with a standard arrangement chromosome, they suppress meiotic crossovers within the inversion. In Drosophila species, heterozygous inversions also cause the interchromosomal effect, whereby the presence of a heterozygous inversion induces a dramatic increase in crossover frequencies in the remainder of the genome within a single meiosis. To date, the interchromosomal effect has been studied exclusively in species that also have high frequencies of inversions in wild populations. We took advantage of a recently developed approach for generating inversions in Drosophila simulans, a species that does not have inversions in wild populations, to ask if there is an interchromosomal effect. We used the existing chromosome 3R balancer and generated a new chromosome 2L balancer to assay for the interchromosomal effect genetically and cytologically. We found no evidence of an interchromosomal effect in D. simulans. To gain insight into the underlying mechanistic reasons, we qualitatively analyzed the relationship between meiotic double-strand break formation and synaptonemal complex assembly. We find that the synaptonemal complex is assembled prior to double-strand break formation as in D. melanogaster; however, we show that the synaptonemal complex is assembled prior to localization of the oocyte determination factor Orb, whereas in D. melanogaster, synaptonemal complex formation does not begin until Orb is localized. Together, our data show heterozygous inversions in D. simulans do not induce an interchromosomal effect and that there are differences in the developmental programming of the early stages of meiosis.

}, doi = {10.1093/genetics/iyae084}, author = {Bowen Man and Elizabeth Kim and Alekhya Vadlakonda and David L Stern and Nicole Crown} } @article {45803, title = {What you didn{\textquoteright}t know about evo-devo}, journal = {Development}, volume = {130}, year = {2003}, month = {12/2003}, pages = {5560-5561}, abstract = {

As most of us are aware, today{\textquoteright}s primary school, high school and undergraduate biology programs are struggling to incorporate even a fraction of the {\textquoteright}molecular revolution{\textquoteright}of biological knowledge and technologies that surround us. In the first term alone, life science and biology classes of the new millennia routinely cover condensed versions of the year-long classes taught in the 60s, 70s and 80s. Teachers no longer have the luxury of spending half a year presenting Mendel and his peas.

}, doi = {10.1242/dev.00767}, author = {David L Stern} } @article {45805, title = {Phylogeny of the Tribe Cerataphidini (Homoptera) and the Evolution of the Horned Soldier Aphids}, journal = {Evolution}, volume = {52}, year = {1998}, month = {02/1998}, pages = {155-165}, abstract = {

The horned soldier aphids of the Cerataphidini, unlike most social insects that reside in nests, live on the open surface of plants. The lack of a nest and other obvious ecological correlates makes it unclear why secondary-host soldiers might have evolved. Here I present a molecular phylogenetic analysis of 32 species of the Cerataphidini, including 10 species from the genera Ceratovacuna and Pseudoregma that produce horned soldiers. The phylogeny suggests that horned soldiers evolved once and were lost once or twice. Most horned soldiers are a morphologically specialized caste and two species that have unspecialized soldiers are independently derived from species with specialized castes. The genus Ceratovacuna appears to have undergone a relatively rapid radiation. Mapping secondary-host plants and geographic ranges onto the phylogeny suggests that bamboos were the ancestral secondary-host plants and that the Asian tropics and subtropics were the ancestral geographic regions for the genera Astegopteryx, Ceratoglyphina, Ceratovacuna Chaitoregma, and Pseudoregma and possibly for the entire tribe. There is evidence for vicariant events that separate the tropical and subtropical lineages in all of the major lineages of the tribe and for dispersal of some lineages. Based on these results, I present hypotheses for the causes and consequences of horned-soldier evolution.

}, url = {http://www.jstor.org/stable/2410930}, author = {David L Stern} } @article {45816, title = {Phylogenetic evidence that aphids, rather than plants, determine gall morphology}, journal = {Proceedings of the Royal Society of London. Series B: Biological Sciences}, volume = {260}, year = {1995}, pages = {85-89}, abstract = {

Many diverse taxa have evolved independently the habit of living in plant galls. For all but some viral galls, it is unknown whether plants produce galls as a specialized plant reaction to certain types of herbivory, or whether herbivores direct gall development. Here I present a phylogenetic analysis of gallforming cerataphidine aphids which demonstrates that gall morphology is extremely conservative with respect to aphid phylogeny, but variable with respect to plant taxonomy. In addition, the phylogeny reveals at least three host plant switches where the aphids produce galls most similar to the galls of their closest relatives, rather than galls similar to the galls of aphids already present on the host plant. These results suggest that aphids determine the details of gall morphology essentially extending their phenotype to include plant material. Based on this and other evidence, I suggest that the aphids and other galling insects manipulate latent plant developmental programmes to produce modified atavistic plant morphologies rather than create new forms de novo.

}, doi = {10.1098/rspb.1995.0063}, url = {http://rspb.royalsocietypublishing.org/content/260/1357/85.short}, author = {David L Stern} } @article {45819, title = {Aphid soldiers discriminate between soldiers and non-soldiers, rather than between kin and non-kin, in Ceratoglyphina bambusae}, journal = {Animal behaviour}, volume = {42}, year = {1991}, pages = {865-866}, abstract = {

Examined kin discrimination and colony defense in soldier-producing aphids from the surface of 3 galls. Soldiers always attacked conspecific nonsoldiers, regardless of origin, and never attacked conspecific soldiers. Soldier attacks of nonsoldiers may exclude unrelated nonsoldier aphids from the gall where they would propagate and compete with resident aphids. (PsycINFO Database Record (c) 2012 APA, all rights reserved)

}, doi = {10.1016/S0003-3472(05)80135-6}, url = {http://psycnet.apa.org/psycinfo/1992-15421-001}, author = {Shigeyuki Aoki and Utako Kurosu and David L Stern} } @article {45821, title = {Wing buzzing by male orchid bees, Eulaema meriana (Hymenoptera: Apidae)}, journal = {Journal of the Kansas Entomological Society}, volume = {64}, year = {1991}, pages = {88-94}, abstract = {

Male orchid bees of the species Eulaema meriana buzz their wings while stationary at territory perches. During buzzing, wings are first positioned laterally and then moved in a plane parallel to the ground, which probably generates a substantial airflow past the body. Within a perching episode, the ratio of buzz to pause duration decreases nonlinearly. The incidence of wing buzzing increases with ambient temperature and with duration of activity. Bees never defended territories when ambient temperatures exceeded 28.5{\textdegree}C. Wing buzzing may be a visual or acoustic display to conspecifics, although the brightly colored abdomen is never obscured by the wings during buzzing, and the sounds of wing buzzing are low in amplitude. The increase in buzzing frequency with increased ambient temperature and the nonlinear decrease in buzz to pause duration during perching suggest that wing buzzing may be a thermoregulatory mechanism.

}, url = {http://www.jstor.org/stable/25085249}, author = {David L Stern and Robert Dudley} } @article {45823, title = {Agonistic interactions between ants and gall-living soldier aphids}, journal = {Journal of Ethology}, volume = {8}, year = {1990}, pages = {139-141}, issn = {0289-0771}, doi = {10.1007/BF02350284}, author = {Utako Kurosu and David L Stern and Shigeyuki Aoki} }