Mastication-related neurons in the orofacial first somatosensory cortex of awake cats

In the orofacial area of the first somatosensory cortex (SI), we recorded single unit activity from 699 neurons in 11 awake cats. Fifty-two percent (362/699) were mastication-related neurons (MRNs) showing activity related to some aspects of masticatory movements. MRNs were divided into three types by their activity patterns: (1) the rhythmical type, showing rhythmical bursts in pace with the masticatory rhythm; (2) the sustained type, showing a sustained firing during the period of taking food and (3) the transient (biting) type, showing intense discharges in coincidence with biting hard food. MRNs had mechanoreceptive fields in the perioral, tongue, periodontal and mandibular regions. The activities of perioral rhythmical-MRNs, mandibular transient-MRNs, tongue rhythmical-MRNs and periodontal transient-MRNs were correlated with food texture, while perioral rhythmical-MRNs, perioral sustained-MRNs and tongue sustained-MRMs were not. Both facial and intraoral MRNs were scattered throughout the facial and intraoral projection areas in SI. These findings provide evidence that the orofacial SI monitors masticatory movements for food ingestion.     

Life history and host specificity of the Japanese flea beetles Trachyaphthona sordida and T. nigrita (Coleoptera: Chrysomelidae), potential biological control agents against skunk vine, Paederia foetida (Rubiaceae), in the southeastern parts of the United States and Hawaii

Skunk vine, Paederia foetida (Rubiaceae), is native to Asia and has been recognized as an invasive weedy vine of natural areas in Florida and Hawaii. Two insects, Trachyaphthona sordida and Trachyaphthona nigrita (Coleoptera: Chrysomelidae) from Japan are being considered as potential biological control agents against skunk vine. To gather fundamental information on their biology, we carried out field surveys and laboratory experiments in Kyushu, southern Japan, between 2003 and 2006. We found that T. sordida is commonly distributed in Kyushu and T. nigrita is restricted to the southern parts of Kagoshima Prefecture on the southern part of Kyushu. These species are fundamentally univoltine and adults appear in late April to early July. Trachyaphthona sordida overwinters as mature larvae and T. nigrita as mature larvae or rarely as adults. Larvae of both species feed on fine roots of P. foetida in the field and Serissa foetida (Rubiaceae) under rearing conditions, and they appear to have tribe‐level host specificity in their host range. On the basis of these results, we suggest that both species are suitable as biological control agents.     

Craniological differentiation between European wildcats (Felis silvestris silvestris), African wildcats (F. s. lybica) and Asian wildcats (F. s. ornata): implications for their evolution and conservation

Intraspecific diversification of the wildcat (Felis silvestris), including the European wildcat (F. s. silvestris), the Asian wildcat (F. s. ornata) and the African wildcat (F. s. lybica), was examined based on 39 cranial morphology variables. The samples of free‐ranging cats originated from Britain, Europe, Central Asia and southern Africa, consisting of both nominal wildcat specimens (referred to henceforth as ‘wildcats’) and nominal non‐wildcat specimens (‘non‐wildcats’) based on museum labels. The skull morphology of ‘wildcats’ from Britain and Europe is clearly different from that of ‘wildcats’ of Central Asia and southern Africa. The latter are characterized especially by their proportionately larger cheek teeth. On the basis of principal component, discriminant function and canonical variate analyses, the skull morphology of British ‘non‐wildcats’ is less distinct than is that of British ‘wildcats’ from the skull morphologies of ‘wildcats’ of Central Asia and southern Africa. On the other hand, the skull morphology of southern African ‘non‐wildcats’ is as distinct from those of ‘wildcats’ of Britain and Europe as is that of southern African ‘wildcats’. We suggest that the evolution of the modern wildcat probably consisted of at least three different distribution expansions punctuated by two differentiation events: the exodus from Europe during the late Pleistocene, coinciding with the emergence of the steppe wildcat lineage (phenotype of Asian–African wildcat), followed by its rapid range expansion in the Old World. The second differentiation event was the emergence of the domestic cat followed by its subsequent colonization of the entire world with human assistance. Considering the recent evolutionary history of, and morphological divergence in, the wildcat, preventing hybridization between the European wildcat and the domestic cat is a high conservation priority. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 83 , 47–63.     

Change in the Template Specificity of RNA Phage SP-Replicase by the <Emphasis Type="Italic">E. coli</Emphasis> Cell Component

Qβ-REPLICASE was isolated from E. coli infected with the RNA bacteriophage Qβ as RNA-dependent RNA polymerase which had template specificity¹. RNA phage SP², which is distinct from RNA phages isolated previously^3,4, has been isolated in our laboratory and SP-replicase⁵ was purified from E. coli infected with SP-phage. SP-replicase has a template specificity different from that of Qβ-replicase. By using this new RNA-replicase, comparison between two distinct replicases has become possible.     

Enzyme Electrophoretic Evidence for Diploidy in Japanese Woodwardia japonica (L.f.) Sm. (Blechnaceae, Pteridophyte) with 2n= 68

Abstract Enzyme-electrophoretic variation was examined in sporophytes of Woodwardia japonica (2n= 68) and segregation was examined in gametophytes. Despite the high chromosome number, W. japonica displayed disomic segregation of isoenzyme patterns. This and karyotype analyses indicate that W. japonica is a diploid derived from a base number of either x= 17 or x= 34.     

INCORPORATION OF RADIOACTIVE CARBON FROM H14CO3-INTO SUGAR CONSTITUENTS BY A BROWN ALGA, EISENIA BICYCLIS, DURING PHOTOSYNTHESIS AND ITS FATE IN THE DARK

When the fronds of Eisenia bicyclis were exposed to H¹⁴CO₃^–in the light, the radioactive carbon was rapidly incorporatedinto mannitol. Even after illumination of such a short periodas 5 min, about seventy percent of the total radioactivity incorporatedwas found in this compound, and the specific radioactivity ofthis alcohol decreased very rapidly during the subsequent darkincubation. Among various cellular polysaccharides examined,only laminaran showed a similar quick response with respectto the specific radioactivity change. On the basis of thesefindings it was concluded that mannitol and laminaran form storagesubstances in the brown alga, and they are possibly interchangeableas sucrose and starch do in higher plants. ¹This work was partly reported at the 27th Annual Meeting ofthe Botanical Society of Japan, Nagoya, 1962, and at the 28thAnnual Meeting of the Botanical Society of Japan, Okayama, 1963. ²Contribution from the Shimoda Marine Biological Station, TokyoKyoiku University, No. 149.     

Regulation of growth response to water stress in the soybean primary root. I. Proteomic analysis reveals region‐specific regulation of phenylpropanoid metabolism and control of free iron in the elongation zone

In water‐stressed soybean primary roots, elongation was maintained at well‐watered rates in the apical 4 mm (region 1), but was progressively inhibited in the 4–8 mm region (region 2), which exhibits maximum elongation in well‐watered roots. These responses are similar to previous results for the maize primary root. To understand these responses in soybean, spatial profiles of soluble protein composition were analysed. Among the changes, the results indicate that region‐specific regulation of phenylpropanoid metabolism may contribute to the distinct growth responses in the different regions. Several enzymes related to isoflavonoid biosynthesis increased in abundance in region 1, correlating with a substantial increase of isoflavonoid content in this region which could contribute to growth maintenance via various potential mechanisms. In contrast, caffeoyl‐CoA O‐methyltransferase, which is involved in lignin synthesis, was highly up‐regulated in region 2. This response was associated with enhanced accumulation of lignin, which may be related to the inhibition of growth in this region. Several proteins that increased in abundance in both regions of water‐stressed roots were related to protection from oxidative damage. In particular, an increase in the abundance of ferritin proteins effectively sequestered more iron and prevented excess free iron in the elongation zone under water stress.     

Sex-specific territorial responses in Tawny Owls Strix aluco

A territorial intruder often poses more of a threat to the territory holder of the same sex as itself. As territorial aggression is associated with costs, aggression shown by birds towards territorial intruders of the opposite sex deserves investigation. This behaviour could arise due to the reproductive value of a mate or through mutualism between members of a pair. We investigated these hypotheses by presenting mated pairs of Tawny Owls Strix aluco with playback of male calls, female calls and a male and female duetting, and recording the number and intensity of responses by the male and female territory holders. Females responded significantly more often to female than to male calls. Males responded equally often to male and female playback. Males which had previously bred successfully with their mate were significantly more likely to respond to female playback in the spring, which suggested males were responding to female playback due to the reproductive value of their mate. There was no evidence of mutualism between members of a pair.