SYSTEMATIC POSITION OF THE COPEPOD LERN AEOCERA CENTROPRISTI

The larvae of the lernaeocerid copepods are as yet very imperfectly known. To extend the knowledge of their morphology, the larvae of Lernaeocera centropristi Pearse, 1947, were re-examined. The larvae had been discovered on the gills of Centropristus striatus (L.) in Beaufort, North Carolina. Their adult stage is still unknown. The examination has shown that the larvae are almost identical with the known larvae of Lernaeocera , but also that they are equipped with additional armament at the base of the mouth-cone. Since the presence of this armament appears to be the main distinguishing feature between the larvae of the genera Lernaeocera and Lernaeenicus , and in view of other small distinctions, it is proposed that Lernaeocera centropristi Pearse, 1947, should be transferred to the genus Lernaeenicus , as L. centropristi (Pearse, 1947).     

The interplay of colour and bioacoustic traits in the differentiation of a Southeast Asian songbird complex

Morphological traits have served generations of biologists as a taxonomic indicator, and have been the main basis for defining and classifying species diversity for centuries. A quantitative integration of behavioural characters, such as vocalizations, in studies on biotic differentiation has arisen more recently, and the relative importance of these different traits in the diversification process remains poorly understood. To provide a framework within which to interpret the evolutionary interplay between morphological and behavioural traits, we generated a draft genome of a cryptic Southeast Asian songbird, the limestone wren‐babbler Napothera crispifrons. We resequenced whole genomes of multiple individuals of all three traditional subspecies and of a distinct leucistic population. We demonstrate strong genomic and mitochondrial divergence among all three taxa, pointing to the existence of three species‐level lineages. Despite its great phenotypic distinctness, the leucistic population was characterized by shallow genomic differentiation from its neighbour, with only a few localized regions emerging as highly diverged. Quantitative bioacoustic analysis across multiple traits revealed deep differences especially between the two taxa characterized by limited plumage differentiation. Our study demonstrates that differentiation in these furtive songbirds has resulted in a complex mosaic of colour‐based and bioacoustic differences among populations. Extreme colour differences can be anchored in few genomic loci and may therefore arise and subside rapidly.     

AN INTERPRETATION OF GULAR SIZE IN SOME ADULT COLEOPTERA

An interpretation of the gular width of some adult beetles has been attempted in terms of absolute head size and the functioning of the mounth-parts. In many groups of beetles (e.g Aphodiinae) the gular width to head width ratio remains approximately constant in species of incresing size, whereas in the Staphylininae it declines because the absolute width of the gula remains nearly constant. Thus in very large Staphylininae the gular sulci meet in the midline. It is suggested that this is due to a relative increase in the size of the mandibular adductors which is necessary to maintain the relstive biting force in larger species, this being required for the penetration of tough prey. It is postulated that this need arises because if the head width were doubled, the volume (and weight) of the head would increase about eight times, whilst the cross-sectional area of the mandibular adductors would only quadruple. A variety of species have been examined in relation to this hypothesis. It is suggested that many Carabidae do not conform because of the presence of stipital retractor muscles between the gular fidges. It also appears that because of these muscles some species have developed a mid-gular apodeme to bear the origins of the labial muscles.     

High efficiency Agrobacterium-mediated transformation of Lycopersicon based on conditions favorable for regeneration

A successful Agrobacterium-mediated transformation system involving a disarmed Ti plasmid is composed of two stages: transformation of cells and recovery of transformed plants. A tissue transformation system with 34% efficiency was developed using stem segments of the interspecific tomato hybrid Lycopersicon esculentum × L. pennellii. This transformation system emphasizes three factors favoring the recovery of transformed plants: 1) promotion of cell division activity at the inoculation site with kinetin in the incubation medium, 2) promotion of adventitious bud initiation by using organized tissue explants in culture, and 3) application of selection at the shoot development stage of adventitious regeneration.Abbreviations MSO Murashige and Skoog (1962) salt medium supplemented with B5 (Gamborg et al. 1968) vitamins, 2.5% sucrose and 0.8% agar - MSc MS0+1.0 mg/l 1-naphthaleneacetic acid and 0.5 mg/l kinetin - MSs1 MS0+1.0 mg/l kinetin - MSs2 MS0+2.0 mg/l kinetin - kn kanamycin sulfate (Sigma) at 100 mg/l - cb carbenicillin (Sigma) at 250 mg/l - cf claforan (cefotaximine sodium, Hoechst-Roussel Pharmuceutical Inc.) at 250 mg/l