Nucleotide sequence of messenger RNA encoding VHDJH and VKJK of a highly conserved idiotype-defined primary response anti-hapten antibody.

The primary humoral immune response of mice to the hapten phthalate (Xmp) is focused upon two adjacent immunodominant negatively charged carboxyl groups on a benzene ring that are in positions meta and para to the azolinkage (i.e., Xmp) to the protein carrier keyhole limpet hemocyanin. A significant fraction of the anti-Xmp antibodies raised in several different inbred mouse strains (BALB/c, DBA/2, A/HeHa; C3H, and SM/J), and many wild mouse populations express a cross-reactive Id, CRIXmp-1. This CRIXmp-1 is conspicuously absent in C57BL/6 mice. In order to obtain a better understanding of the events and parameters that influence the selection and regulation of the primary response B cell repertoire, and to explore the structural basis of Ag binding, we have determined the nucleotide sequence of the entire V region gene complexes, which encode the H and L chains of these highly conserved and dominant CRIXmp-1+ antibodies. Our data establish that the H chain gene complex consists of a single VH germ-line gene that is identical to VH Oxazolone-1, encoding the H chain of another highly conserved and dominant cross-reactive Id family associated with the primary response to Oxazolone. In CRIXmp-1+ Xmp-specific hybridomas this gene is joined to a limited set of D region sequences that express a conserved amino acid motif-GLR. At least three of the five D regions examined are coded for by DFL16.2. This VHD complex can be utilized with one of three different JH region genes (JH1, JH2, and JH4) without any significant effect upon antibody fine specificity or Id. In spite of this lack of JH fidelity all of the CRIXmp-1+ hybridomas have precisely maintained the same length in the H chain CDR3 and FRW4 by altering either the length of the D segment or the length of JH. Nucleotide sequence analysis of the VL gene complex of CRIXmp-1+ anti-Xmp antibodies indicates that the L chain V region is also encoded by a single germ-line gene. The amino acid sequence predicted from the nucleotide sequence of the VKJK from Xmp-specific CRIXmp-1+ hybridomas is identical to the sequence of the anti-arsonate antibody 1210.7, which is the prototype of another Id family (CRI) that is conserved and dominant in BALB/c mice.     

Evolutionary Robotic Approaches in Primate Gait Analysis

Understanding how primates move is particularly challenging because many of the experimentation techniques that would normally be available are unsuitable for ethical and conservation reasons. We therefore need to develop techniques that can maximize the data available from minimally intrusive experimentation. One approach for achieving this is to use evolutionary robotic techniques to build a musculoskeletal simulation and generate movement patterns that optimize some global parameter such as economy or performance, or to match existing kinematic data. If the simulation has a sufficiently high biofidelity and can match experimentally measured performance criteria then we can use it to predict aspects of locomotor mechanics that would otherwise be impossible to measure. This approach is particularly valuable when studying fossil primates because it can be based entirely on morphology and can generate movements spontaneously. A major question in human evolution is the origin of bipedal running and the role of elastic energy storage. By using an evolutionary robotics model of humanoid running we can show that elastic storage is required for efficient, high-performance running. Elasticity allows both energy recovery to minimize total energy cost and also power amplification to allow high performance. The most important elastic energy store on the human hind limb is the Achilles tendon: a feature that is at best weakly expressed among the African great apes. By running simulations both with and without this structure we can demonstrate its importance, and we suggest that identification of the presence or otherwise of this tendon—perhaps by calcaneal morphology or Sharpey’s fibers—is essential for identifying when and where in the fossil record human style running originated.     

The struggle for life: I. Two species

The general equations are discussed describing two species in competition or in symbiosis or feeding one on the other.     

Cation signals rapidly elicited in several different plant species by pinching the leaves

Several plant species (snapbeans, soybeans, tomatoes, and maize)were shown to respond within 3–60 s to pinching a single,fully expanded leaf with a clinical haemostat. The responsewas measured by an increase, as compared to controls, in Ca²⁺, Mg²⁺ and K⁺ concentrations in the exudate from the stump ofstems excised at the first leaf (maize) or cotyledonary nodeat various times after pinching. The enhanced apoplastic cationconcentrations were shown to be transient, diminishing withtime. Usually no response could be measured if excision wasdelayed more than 3 min. The number of pinches affected themagnitude of the response, with one pinch sufficient in mostcases. Our data suggest that transient changes in extracellularcations are involved in signal trans-duction or as a secondmessenger in response to perturbations. Key words: Cations, signalling, Ca²⁺, Mg²⁺, K⁺