The sound of one-hand clapping: handedness and perisylvian neural correlates of a communicative gesture in chimpanzees

Whether lateralization of communicative signalling in non-human primates might constitute prerequisites of hemispheric specialization for language is unclear. In the present study, we examined (i) hand preference for a communicative gesture (clapping in 94 captive chimpanzees from two research facilities) and (ii) the in vivo magnetic resonance imaging brain scans of 40 of these individuals. The preferred hand for clapping was defined as the one in the upper position when the two hands came together. Using computer manual tracing of regions of interest, we measured the neuroanatomical asymmetries for the homologues of key language areas, including the inferior frontal gyrus (IFG) and planum temporale (PT). When considering the entire sample, there was a predominance of right-handedness for clapping and the distribution of right- and left-handed individuals did not differ between the two facilities. The direction of hand preference (right- versus left-handed subjects) for clapping explained a significant portion of variability in asymmetries of the PT and IFG. The results are consistent with the view that gestural communication in the common ancestor may have been a precursor of language and its cerebral substrates in modern humans.     

Tool use, communicative gesture and cerebral asymmetries in the modern human brain

Determining the brain adaptations that underlie complex tool-use skills is an important component in understanding the physiological bases of human material culture. It is argued here that the ways in which humans skilfully use tools and other manipulable artefacts is possible owing to adaptations that integrate sensory-motor and cognitive processes. Data from brain-injured patients and functional neuroimaging studies suggest that the left cerebral hemisphere, particularly the left parietal cortex, of modern humans is specialized for this purpose. This brain area integrates dynamically representations that are computed in a distributed network of regions, several of which are also left-lateralized. Depending on the nature of the task, these may include conceptual knowledge about objects and their functions, the actor's goals and intentions, and interpretations of task demands. The result is the formation of a praxis representation that is appropriate for the prevailing task context. Recent evidence is presented that this network is organized similarly in the right- and left-handed individuals, and participates in the representation of both familiar tool-use skills and communicative gestures. This shared brain mechanism may reflect common origins of the human specializations for complex tool use and language.     

Human handedness and the concept of developmental stability

A model is proposed to explain the etiology of pathological handedness. Developmental instability, caused by elevated genotypic homozygosity, environmental disturbances, or their interaction, overrides programmed laterality and handedness in the same way that it perturbs the bilaterally symmetrical expression of morphological and metric traits. The model predicts that pathological handedness should be elevated among individuals with higher than average homozygosity and individuals who have developed under unfavorable uterine environments. Suggestions are offered for specific populations in which the predictions may be tested.     

Human handedness and scalp hair-whorl direction develop from a common genetic mechanism

Theories concerning the cause of right- or left-hand preference in humans vary from purely learned behavior, to solely genetics, to a combination of the two mechanisms. The cause of handedness and its relation to the biologically specified scalp hair-whorl rotation is determined here. The general public, consisting of mostly right-handers (RH), shows counterclockwise whorl rotation infrequently in 8.4% of individuals. Interestingly, non-right-handers (NRH, i.e., left-handers and ambidextrous) display a random mixture of clockwise and counterclockwise swirling patterns. Confirming this finding, in another independent sample of individuals chosen because of their counterclockwise rotation, one-half of them are NRH. These findings of coupling in RH and uncoupling in NRH unequivocally establish that these traits develop from a common genetic mechanism. Another result concerning handedness of the progeny of discordant monozygotic twins suggests that lefties are one gene apart from righties. Together, these results suggest (1) that a single gene controls handedness, whorl orientation, and twin concordance and discordance and (2) that neuronal and visceral (internal organs) forms of bilateral asymmetry are coded by separate sets of genetic pathways. The sociological impact of the study is discussed.     

Distinct sub-populations of the retinoblastoma protein show a distinct pattern of phosphorylation.

Phosphorylation of the retinoblastoma protein (pRB) is assumed to regulate its growth-controlling function. Moreover, hypophosphorylated and hyperphosphorylated forms of pRB can be distinguished by virtue of the distinct affinities with which they bind to the cell nucleus. This property allows the identification of individual cell nuclei that contain pRB in one or the other form. We show here that after cells emerge from a quiescent (G0) state, conversion of their complement of pRB into a hyperphosphorylated form occurs in late G1, preceding entry into S phase by several hours. Thus, contrary to earlier reports, pRB phosphorylation is not co-ordinated with the G1-S transition and may not directly regulate it. A distinct set of phosphopeptides is found exclusively in those forms of pRB that show the loose nuclear association characteristic of the hyperphosphorylated form of pRB. Another set of phosphopeptides is found with both hypophosphorylated and hyperphosphorylated forms. This suggests the existence of distinct patterns of phosphorylation that are associated with different subsets of pRB molecules. We conclude that substantial phosphorylation of pRB exists in G1 even prior to the hyperphosphorylation point. Cyclin-dependent kinases can cause a liberation of pRB from cell nuclei in vitro. Phosphorylation by members of this kinase family is therefore likely to be directly involved in the change in nuclear affinity in vivo and the associated changes in pRB functioning.     

Paracoccidioides brasiliensis antigen batches from the same isolate show immunological and biochemical differences

We investigated the occurrence of antigenic and biochemical variability among Paracoccidioides brasiliensis antigen batches prepared according to the same protocol. Initially (experiment #1), we analyzed two antigen lots of two human isolates (Bt1 & Bt2), cultured in two media (PYG: bactopeptone, yeast extract, glucose; MMM: McVeigh & Morton medium) in SDS-PAGE and in two immunological tests (imunodiffusion-ID and footpad swelling test-FPT). Afterwards (experiment #2), we compared the antigenic profile of three antigen batches from three human isolates (Bt1, Bt2 & Bt3) by two-dimensional immunoelectrophoresis (2 D-IEP) against a reference system for P. brasiliensis antigens. In experiment #1, there were important intra- and inter-strain antigenic differences between batches of the fungal isolates cultured on both media. The block titration of the antigen batches for the immunological tests revealed correlation between protein concentration and biological activity in ID and no correlation in FPT. In experiment #2, the reference system for P. brasiliensis showed 26 antigen peaks. There were important differences between batches prepared from the same isolate and between batches from different isolates. Our data suggested the occurrence of instability in the synthesis of antigenic components by a same P. brasiliensis isolate, under controlled incubation conditions.     

Two crystal forms of the restriction enzyme MspI-DNA complex show the same novel structure

The crystal structure of the Type IIP restriction endonuclease MspI bound to DNA containing its cognate recognition sequence has been determined in both monoclinic and orthorhombic space groups. Significantly, these two independent crystal forms present an identical structure of a novel monomer-DNA complex, suggesting a functional role for this novel enzyme-DNA complex. In both crystals, MspI interacts with the CCGG DNA recognition sequence as a monomer, using an asymmetric mode of recognition by two different structural motifs in a single polypeptide. In the crystallographic asymmetric unit, the two DNA molecules in the two MspI-DNA complexes appear to stack with each other forming an end-to-end pseudo-continuous 19-mer duplex. They are primarily B-form and no major bends or kinks are observed. For DNA recognition, most of the specific contacts between the enzyme and the DNA are preserved in the orthorhombic structure compared with the monoclinic structure. A cation is observed near the catalytic center in the monoclinic structure at a position homologous to the 74/45 metal site of EcoRV, and the orthorhombic structure also shows signs of this same cation. However, the coordination ligands of the metal are somewhat different from those of the 74/45 metal site of EcoRV. Combined with structural information from other solved structures of Type II restriction enzymes, the possible relationship between the structures of the enzymes and their cleavage behaviors is discussed.     

The relation of canine size to pattern and extent of attrition in baboons

For most genera of animals the association between dental morphology and diet is such that inferences concerning the diet can be made on the basis of the dentition alone. The canine is the one tooth that appears exempt from such generalisation and exhibits a wide range of variability of size and shape in all groups. In order to determine the effect of dimorphism of the canine on the dental apparatus, male and female specimens of Theropithecus and Papio baboons were examined. Occlusal relationships and dental pathology for 21 Theropithecus and 40 Papio skulls were recorded, and crown height measurements obtained for maxillary incisors, buccal and lingual molar cusps. Attrition was the most common and severe cause of abscess formation in older animals: the pattern of attrition differed in adult males and females, the latter showing more wear of the incisor and lingual molar cusps. Partial correlations for incisor, buccal and lingual molar cuspal crown height show a significant correlation between incisor and lingual cusp attrition in juveniles of both sexes and adult females (p < 0.01). Adult males show no correlation of attrition. It is proposed that the correlation of incisor and lingual molar cusp attrition is associated with anterior-posterior grinding movements, such as take place during incision, that the large canine present in the male limits such movements, the sharp blade-like canine being employed as a cutting tool. This use of the canine by reducing functional demands on other teeth, prolongs the utility of the dental apparatus, and hence the lifespan of its possessor.     

Esr genes show different levels of expression in the same region of maize endosperm

Esr genes share high homology among each other, code for small hydrophilic proteins, and are expressed in a restricted region of maize endosperm surrounding the embryo. We show here that not only Esr2 but also Esr1 and Esr3 are expressed in maize, and that the relative contribution of Esr1, Esr2 and Esr3 to total Esr mRNA is 17%, 55% and 28%, respectively. DNA sequence analysis of putative promoter fragments ranging from 0.53 kb to 3.54 kb revealed the presence of retrotransposons related to the Zeon and Cinful families in the distal parts of the promoters. The proximal parts show high homology that extended over 504bp between Esr2 and Esr3, and 265bp between Esr1 and the other two genes. The most conspicuous potential cis element is a fully conserved tandem repeat of the sequence CTACACCA close to the respective open reading frames (ORFs). By the analysis of transgenic maize plants carrying promoter-Gus fusions, it was shown that all three cloned upstream fragments contain functional promoters, that the spatial activity of all three Esr promoters is identical, and that the cis element(s) responsible for the expression in the embryo surrounding region reside in the 265 bp upstream of the respective ORFs.     

Human seminal proteinase and prostate-specific antigen are the same protein

Human seminal proteinase and prostate-specific antigen (PSA) were each isolated from human seminal fluid and compared. Both are glycoproteins of 32-34 kDa with protease activities. Based on some physicochemical,enzymatic and immunological properties,it is concluded that these proteins are in fact identical.The protein exhibits properties similar to kallikrein-like serine protease, trypsin,chymotrypsin and thiol acid protease.Tests of the activity of the enzyme against some potential natural and synthetic substrates showed that bovine serum albumin was more readily hydrolysed than casein.The results of this study should be useful in purifying and assaying this protein.Based on published studies and the present results,the broad proteolytic specificity of human seminal proteinase suggests a role for this protein in several physiological functions.     

Spatial pattern in a troop of yellow baboons (Papio cynocephalus) in Tanzania

Observations of adult and subadult yellow baboons (Papio cynocephalus) revealed class differences in spatial pattern both during movement and when at rest. males tended to spend slightly more time on the periphery than did females, and travelled more at the front. Positions of males reflected their association with females: younger and older adults were more peripheral, while prime adults were focal. Positions of adult females reflected their reproductive state: mothers of young infants were gregarious, but pregnant females were peripheral and travelled at the sides. Lower-ranking females were also more peripheral. These patterns are discussed in relation to male and female reproductive differences as well as to predation.     

Fusicoccin- and IAA-induced elongation growth share the same pattern of K+ dependence

The dependence of growth induced by the fungal toxin fusicoccin (FC) on the K+ content of the incubation medium was investigated in abraded maize coleoptiles. If the divalent ion Ca2+ was included in the bathing medium, no FC-induced growth occurred in the absence of K+, whereas a strong response was detected in presence of K+. The optimal K+ concentration was in the range of 1-10 mM. With the exception of Rb+, none of the other alkali ions (Na+, Li+, Cs+) could replace for K+ in sustaining FC-induced growth. The potassium channel blocker tetraethylammonium (TEA) reversibly inhibited FC-induced growth. As shown earlier for auxin-induced growth, no strict potassium dependence of FC-triggered elongation was observed in Ca2+ -free media. However, TEA abolished this apparently K+ independent FC-induced growth. It is concluded that FC-induced growth, like auxin-induced growth, requires K+ uptake through K+ channels.     

Tripedal knuckle-walking: a proposal for the evolution of human locomotion and handedness.

A comparative morphological analysis of human and non-human hominoids was conducted in an attempt to determine the mode of locomotion of the protohominid. Although the generalized hominoid anatomy permits variation of locomotion: brachiation, knuckle-walking, etc., minor variations in structure determine which behavior is favored. Arboreal arm swinging requires a flexible forelimb while terrestrial fist or knuckle-walking demands more rigidity of the hand and wrist. It is demonstrated that the large human thumb accompanied by the strong adduction of the thenar, hypothenar, and palmar interosseous muscles offer powerful rigidity to the hand, while fusion of the os centrale with the scaphoid during gestation permits the formation of an arch of carpals which imbue the wrist with the stability necessary for weight bearing. Fascialization of the contrahentes and dorsiepitrochlearis muscles in the human as well as depilation of the middle phalanges; the webbing (syndactyly) of the palm; the direction of the fibers of the interosseous membrane of the forearm; the shape of the puerile annular ligament, and the direction of the human glenoid fossa strongly suggest that the ancestor of man used a knuckle-walking form of locomotion prior to becoming bipedal. A model is presented that suggests that bipedalism was attained through an intermediate stage of tripedalism. The model is based on the fact that man's anatomy is much more asymmetric than that of the great apes. A presumption is made that due to the absence of trees for climbing in the transition from forest to open plain, the protohominid needed to carry tools (stones) at all times for protection. Stones could be carried for long distances on the posterior iliac crest since the weight would be shifted posteriorly over the legs. Pick up, medial rotation and adduction of the stone would employ a two-muscle chain of biceps brachii and latissimus dorsi. On the iliac crest, the stone is posterior to the coronal plane of the glenohumeral joint, and with the contraction of this two-muscle chain, the shoulder on one side is moved posteriorly effecting a semi-erect posture. It is proposed that tripedalism of the protohominid may be an explanation for the handedness unique to hominids.     

Dorsal and ventral cells of cleavage-stage Xenopus embryos show the same ability to induce notochord and somite formation

Cells in the dorsal marginal zone of the amphibian embryo acquire the potential for mesoderm formation during the first few hours following fertilization. An examination of those early cell interactions may therefore provide insight on the mechanisms important for organization of axial structures. The formation of mesoderm (notochord, somites, and pronephros) was studied by combining blastomeres from the animal pole region of Xenopus embryos (32- to 512-cell stages) with blastomeres from different regions of the vegetal hemisphere. The frequency of notochord and somite development was similar in combinations made with dorsal or ventral blastomeres, or with both. Our results show that during early cleavage stages the ventral half of the vegetal hemisphere has the potential to organize axial structures, a property previously believed to be limited to the dorsal region.     

Transcribed and nontranscribed parts of the human ribosomal gene repeat show a similar pattern of distribution in nucleoli.

The distribution pattern of the transcribed and nontranscribed parts of human ribosomal RNA genes were visualized simultaneously in the same cells by nonautoradiographic in situ hybridization. DNA probes labeled with either digoxigenin or biotin were detected in the same cells by different fluorescence systems. The signals from both the transcribed and nontranscribed parts showed a similar distribution pattern. This finding is not compatible with the conclusion, suggested by earlier studies, that the transcribed and nontranscribed parts of the rRNA genes are located at different sites within the nucleoli or in different nucleolar components.     

EPR studies show that all lanthanides do not have the same order of binding to calmodulin

Calmodulin, spin labeled at Tyr-99, has been titrated with the lanthanides La3+, Nd3+, Eu3+, Tb3+, Er3+ and Lu3+ as well as Ca2+ and Cd2+. The titration was monitored by EPR and changes in mobility of the spin label, due to binding into the labeled site and protein conformational change, were observed. Comparison of these titration curves with theoretical binding curves for the various calmodulin-metal species, show that different lanthanides have different high affinity sites. Three basic categories were observed, with Lu3+ and Er3+ behaving like Ca2+, Eu3+ and Tb3+ binding in the opposite order from Ca2+, and La3+ and Nd3+ different from either Ca2+ or Tb3+.     

Molecular markers show a complex mosaic pattern of wheat-Thinopyrum intermedium translocations carrying resistance to YDV

Thinopyrum intermedium translocations derived from the wheat (Triticum aestivum L.) substitution line P-29 were previously characterized by RFLP. We have further analyzed these lines and additional related germplasm with publicly available STS and SSRs. Primers which showed a polymorphism between wheat and P-29, were tested in all recombinant and nulli-tetrasomic lines confirming their position on chromosome 7D. The resulting 7D/7E chromosome maps appeared as a mosaic of wheat and Th. intermedium chromatin sections. To verify the composition of the translocation lines suggested by the RFLP-PCR map, F₂ progeny of two crosses (CS/216-1 and CS/260-1) were analyzed with molecular markers. Both populations gave an unexpectedly diverse number of recombinant individuals, suggesting that interstitial translocations occur more frequently than previously thought. This analysis also showed that there is a wide range in the number and position of the interstitial translocations within a given line such as the mosaic chromosome in recombinant line 260-1/CS-26, which has four Th. intermedium chromosome segments. Phenotypic data of the two populations suggested the presence of one gene which we have called Bdv3 to differentiate it from the previously reported orthologous gene Bdv2. Using the PCR-based molecular markers identified in this study, 5 out of 12 elite lines that showed good yields and no YDV symptoms contained Th. intermedium chromatin. Due to the multiple components involved in the YDV disease complex, combining selection for YDV resistance with the molecular markers and maps identified in this study will increase the efficiency of introgressing Th. intermedium chromatin containing YDV resistance or other beneficial traits into elite wheat germplasm.     

Proton pump inhibitors while belonging to the same family of generic drugs show different anti-tumor effect

Context: Tumor acidity represents a major cause of chemoresistance. Proton pump inhibitors (PPIs) can neutralize tumor acidity, sensitizing cancer cells to chemotherapy.

Objective: To compare the anti-tumor efficacy of different PPIs in vitro and in vivo.

Materials and methods: In vitro experiments PPIs anti-tumor efficacy in terms of cell proliferation and cell death/apoptosis/necrosis evaluation were performed. In vivo PPIs efficacy experiments were carried out using melanoma xenograft model in SCID mice.

Results: Lansoprazole showed higher anti-tumor effect when compared to the other PPIs. The lansoprazole effect lasted even upon drug removal from the cell culture medium and it was independent from the lipophilicity of the PPIs formulation.

Discussion: These PPIs have shown different anti-tumoral efficacy, and the most effective at low dose was lansoprazole.

Conclusion: The possibility to contrast tumor acidity by off-label using PPIs opens a new field of oncology investigation.