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81.
We report observational data on behavioral laterality in 10 captive bonobos (Pan paniscus)at the San Diego Zoo. The unimanual measures include carrying, leading limb in locomotion, self-touching, face-touching, reaching,
and gestures. We also recorded bimanual feeding in these subjects. A significant population level left-hand bias exists for
carrying. Right-hand biases occur for leading limb in locomotion and gestures. During bimanual feeding, the bonobos hold food
items with the left hand while feeding with the right hand. Overall, bonobos exhibit behavioral asymmetries that are similar
to previous findings in other pongid ape species. The asymmetries in gestures and bimanual feeding represent novel findings
with theoretical implications for the origins of tool use and language. 相似文献
82.
Condensed and dispersed chromatin fractions were isolated from human placental nuclei. The DNA of each fraction was purified and characterised by isopycnic centrifugation, thermal fractionation on hydroxylapatite (HAP) and sequence complexity studies. The DNAs had identical buoyant densities in neutral CsCl (1.698 g/cm3) and similar melting profiles on HAP. Analytical ultracentrifugation in Ag+-Cs2SO4, however, showed that satellite DNAs were present in the condensed fraction DNA (DNAC) but were not visible in the dispersed fraction DNA (DNAD). In addition, DNAC was found to be enriched in highly reiterated sequences (20% reassociated by C0t 10?3) which can be correlated with the presence of satellite DNAs, whereas DNAD contained only 3% of these fast reassociating sequences. In contrast DNAD contained 30% intermediate sequences (reassociating between C0t 10?3 and C0t 100) which represent only 10% of DNAC. The reassociated highly repeated sequences of DNAC showed the presence of two components in both CsCl density gradients and HAP thermal elution studies. This suggests that either there are sequence relationships resulting in partial mismatching between the different highly repeated DNA sequences in this fraction, or that highly repeated sequences are associated with less repetitious DNA. The results are discussed in terms of possible differences in genetic activity between the chromatin fractions. 相似文献
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The ontogeny of large, globular, epidermal cytoplasmic inclusions (ECI) in P. virgatum roots was studied at the ultrastructural level. These ECI were seen to originate in meristematic cells as small electron translucent vesicles. Subsequently, the ECI, which appeared to be temporary storage sites, were seen to enlarge and increase in density by accumulating masses of a granular matrix as well as some small vesicular inclusions. In the zone of elongation, as the epidermal cells matured, the ECI within each cell gradually fused and the contents were lost. The pattern of the ontogeny of the ECI in the growing epidermal cells was consistent with the presence of cells of different physiologies in the zone of cell elongation of these roots. 相似文献
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