Michael Barton

The phylogeny of the red panda (Ailurus fulgens): evidence from the forelimb.

Within the order Carnivora, the phylogeny of the red panda (Ailurus fulgens) is contentious, with morphological and molecular studies supporting a wide range of possible relationships, including close ties to procyonids, ursids, mustelids and mephitids. This study provides additional morphological data, including muscle maps, for the forelimb of Ailurus, based on the dissection of four cadavers from the National Zoological Park, Washington, DC, USA. The red panda forelimb is characterized by a number of primitive features, including the lack of m. rhomboideus profundus, a humeral insertion for m. cleidobrachialis, the presence of mm. brachioradialis, articularis humeri and coracobrachialis, a single muscle belly for m. extensor digitorum lateralis with tendons to digits III–V, four mm. lumbricales, and the presence of mm. flexor digitorum brevis manus, adductores digiti I, II and V, and abductor digiti I and V. Red pandas resemble Ailuropoda, mustelids and some procyonids in possessing a soft tissue origin of m. flexor digitorum superficialis. In addition, red pandas are similar to ursids and procyonids in having a variable presence of m. biceps brachii caput breve. Furthermore, Ailurus and some ursids lack m. rhomboideus capitis. The forelimb muscle maps from this study represent a valuable resource for analyzing the functional anatomy of fossil ailurids and some notes on the Miocene ailurid, Simocyon batalleri, are presented.

Numb regulates Notch1, but not Notch3, during myogenesis

In the vertebrate embryo, skeletal muscle is derived from the myotome of the somites. Notch1-3 demonstrate overlapping and distinct expression patterns in mouse somites. Notch1 and Notch2 have been shown to be inhibitors of skeletal myogenesis. The current data demonstrate that Notch3 also is an effective inhibitor of MyoD induced myogenesis. Numb, an adaptor protein that promotes Notch degradation by recruiting the E3 ubiquitin ligase, Itch, is limited in expression to dividing cells of the dorsal medial lip of the dermomyotome and the myotome itself. Here the specificity of the four protein isoforms of Numb for the Notch receptors was examined. In transcription and myogenic differentiation assays, Notch1 was consistently negatively regulated by all four Numb isoforms, and Notch3 was not a target for Numb. Notch2 however was variably affected. Subsequent analyses showed that unlike Notch1, that Notch3 was not polyubiquitinated, nor degraded when co-expressed in cells with Numb. These data provide the first observations that Notch receptors are variably affected by Numb and will be important for the interpretation of the function of Notch and Numb interactions during the development of many different cells and tissues.

AEA 2012 Conference Reading: Socioecological dynamics at the time of Neolithic transition in Iberia

Abstract The Western Mediterranean, spanning southern Italy to Portugal, can be considered a single archaeological unit where the diagnostic characteristics of Early Neolithic contexts share common elements, marked by the spread of Cardium-Impressed ceramics. Although some consensus exists regarding the origin of these wares in southern Italy, the debate surrounding its process of expansion to the west remains open. Iberia is a key region for the analysis of the neolithisation process due to its location at the end of the Neolithic Mediterranean expansion. This view includes the problems linked with the mechanism of this spread and the evolutionary dynamics of the early agricultural societies. Our goals are to evaluate the rich archaeological and palaeoenvironmental database produced by recent decades of research in this area in order to address issues related to the Neolithic Transition. We especially deal with the role played by climatic events in the observed dynamics of the last Mesolithic and the Early Neolithic (ca. 8500–6900 cal BP).