Ventral Limbs Research Articles

A retrospective epidemiological study of sarcoptic mange in koalas (Phascolarctos cinereus) using wildlife carer admission records

Outbreaks of sarcoptic mange are sporadically reported in koala populations across Australia, but disease characteristics (e.g., distribution across the body) remain poorly understood. In an area of Northern Victoria regular cases coming into care suggest mange may have become enzootic, and here we characterise those koala mange admission records. In 18% (n = 10) of mange affected koala reports that had a recorded outcome (n = 55), the animals died before the carers could locate them, and of the remaining 45 koalas that were alive upon carer arrival, 80% (n = 36) had to be euthanised due to severe mange. The number of admissions varied among years (highest observed in 2019), and over 60% of affected koala admissions were male. Male admissions peaked in austral spring and again in late austral summer-autumn (mating and birthing seasons), with female admissions only exhibiting the latter peak (birthing season). Fissures of the epidermis of the front paws occurred in 100% of admitted koalas, with 70% also showing these signs elsewhere on ventral surfaces or limbs. Only male koalas had signs of mange on the chest and face, and only female koalas had signs of mange on their back. Collectively, this study suggests sarcoptic mange can be a severe disease in koalas, and that male koalas may play an important role in seasonal transmission dynamics. We discuss how these findings may help inform intervention strategies.

Schistonchus pumilae n. sp. isolated from syconia of a creeper fig, Ficus pumila L. from the Japanese warm temperate zone

Summary A Schistonchus species was isolated from the syconia of the creeping fig, Ficus pumila, collected from Miyazaki, Japan. The nematode was considered an undescribed species based on its typological characters, molecular profiles (near full length of small subunit and D3 expansion segment of large subunit of RNA) and phylogenetic status inferred from these two loci. The new species is characterised by the presence of flagellate sperm, spicule possessing small condylus, triangular rostrum with bluntly pointed tip and clear dorsal and ventral limbs, structure and arrangement of male caudal papillae, i.e., presence of papilliform P3 and P3a and small and gland opening-like P4 (glandpapillae), relatively short post-uterine sac and female tail forming elongate conoid. It is phylogenetically close to S. hirtus. However, the new species is distinguished from other nominal Schistonchus species by its female tail shape forming elongate conoid, the structure and arrangement of male caudal papillae and several other typological characters. In addition, the host fig of the nematode, F. pumila, is a creeper fig species belonging to subgenus Synoecia (section Rhizocladus; subsection Plagiostigma), from which no fig-associated nematode has been reported so far, i.e., the present study is the first report of Schistonchus (and other syconia-inhabiting nematodes) from the Ficus subgenus Synoecia.

Description of Ruehmaphelenchus kuroshioi n. sp. and R. interjectus n. sp. (Tylenchomorpha: Aphelenchoididae) isolated from ambrosia beetles, Euwallacea spp. (Scolytinae), from Japan

Summary Two Ruehmaphelenchus species were isolated from the ambrosia beetles Euwallacea kuroshio and E. interjectus, collected from Okinawa and Kagoshima, Japan, respectively. Both nematodes were successfully cultured on a lawn of the grey mould Botrytis cinerea. Morphological observation and molecular characterisation revealed that both species are undescribed; therefore, the nematodes are described herein as R. kuroshioi n. sp. and R. interjectus n. sp. Phylogenetically, both species are closely related to R. formosanus, R. fujiensis, R. digitulus and R. asiaticus. Ruehmaphelenchus kuroshioi n. sp. is characterised by a conical male and female tail, which has a terminal projection (mucron), small male spicule with a weakly-developed triangular condylus, dorsal and ventral limbs that are connected to each other by three different tissues, and clearly separated distal pairs of genital papillae (P3 and P4). However, R. kuroshioi n. sp. can be distinguished from its close relatives by a combination of male and female tail characters and its distinctive phylogenetic status. Ruehmaphelenchus interjectus n. sp. is almost identical to R. formosanus, sharing characteristic lateral spikes of the spicule; they form a well-supported phylogenetic clade. However, R. interjectus n. sp. is distinguished from R. formosanus by morphometric values and ribosomal RNA, i.e., a 6-bp difference from the ca 1.7 kb molecular sequence of the 18S ribosomal RNA of R. formosanus, which warrants independent species status.

A Cambrian fossil from the Chengjiang fauna sharing characteristics with gilled lobopodians, opabiniids and radiodonts

Parvibellus atavus gen. et sp. nov. from the Early Cambrian Chengjiang fauna of China is a small fossil having a distinct cephalic region bearing a pair of lateral projections and a circular, ventral mouth. The trunk bears eleven pairs of probably flap-like appendages and a short pair of terminal projections. This character combination is unique for the Chengjiang biota. A circular ventral mouth is seen in Radiodonta and in some of the gilled lobopodians which are thought to be among the radiodont’s closest relatives. P. atavus, gilled lobopodians, opabiniids, and radiodonts also share the putative character of flap-like appendages along the trunk. However, the new fossil differs from radiodonts and gilled lobopodians by the absence of enlarged and/or raptorial frontal appendages. It also differs from gilled lobopodians by lacking in ventral lobopod limbs and from radiodonts by lacking in stalked eyes. It provisionally resolves as a sister-group to a clade containing the gilled lobopodians, opabiniids, and radiodonts, and could potentially be part of an early radiation of the nektonic lower stem—Euarthropoda.

Gross morphological and morphometric study of the upper respiratory system of the African giant rat (Cricetomys gambianus, Waterhouse 1840).

The nose is a structurally and functionally complex organ in the upper respiratory tract. It not only serves as the principal organ for the sense of smell, but also functions to efficiently filter, warm, and humidify inhaled air before the air enters the more delicate distal tracheobronchial airways and alveolar parenchyma of the lungs. Despite the volume of published studies on the biology of rodents, there is no information on the gross upper respiratory morphology of the African giant rat (AGR) in the available literature. Hence, this study aimed to examine the anatomy of the turbinates, their meatuses, and the morphometry of the nasal cavity. The following were found and reported in this study: (a) There were three nasal conchae in AGR: the nasoturbinate, which was the largest; the ethmoturbinate, which was composed of one well-developed ectoturbinate and three well-developed endoturbinates; and the maxilloturbinate, which was fusiform, short, and branched. (b) Three major meatuses were observed: the dorsal nasal meatus, which was the longest and widest; the middle nasal meatus, which was without limbs but had a deep oval caudal recess; and the ventral nasal meatus, which directly continued caudally into the nasopharyngeal meatus. (c) Four ethmoturbinates with four slit-like meatuses were observed, each with dorsal and ventral limbs; the first contacted the middle nasal meatus but not the nasopharyngeal meatus. (d) There were three paranasal sinuses: one sphenoid, two frontal, and two palatine sinuses. The data obtained are relevant to pathologists and eco-morphologists, considering the burrowing habitat and behaviors of AGR, and provide baseline data for more investigative studies.

Complex malformations involving the fetal body wall – definition and classification issues

The objective of the study is to analyse the sonographic features, cytogenetic results and pregnancy outcomes in complex malformations involving the body wall in a large cohort of fetuses with regard to different definitions proposed in the literature. A retrospective study on 96 fetuses with complex malformations comprising ventral wall, craniofacial structures, limbs and umbilical cord that were evaluated between 1997 and 2015. The most common sonographic finding was an extensive ventral wall defect (95.8%; 92/96) comprising liver (94.6%; 87/92), intestine (82.6%; 76/92), heart (17.4%; 16/92) and bladder (8.7%; 8/92). Acrania and encephalocoele were observed in 24 and 9 fetuses (25.0%, 24/96; 9.4%, 9/96), respectively. Limb anomalies were present in 54 fetuses (56.3%; 54/96). Rudimentary or absent umbilical cord was observed in 62 fetuses (64.6%; 62/96). In 79 fetuses, there were additional multiple structural anomalies detected prenatally. None of the currently used definitions encompasses all possible phenotypes of body wall defects present in our cohort. Chromosomal aberrations were seen in 8 out of 60 cases with conclusive cytogenetic result (13.3%, 8/60). Chromosomal anomalies are common, and karyotyping should be offered. There is a need for a more rigorous classification of complex malformations in order to better understand the underlying pathophysiology. © 2017 John Wiley & Sons, Ltd.

Bursaphelenchus kesiyae n. sp. (Nematoda: Aphelenchoididae), isolated from dead wood of Pinus kesiya Royle ex Gordon (Pinaceae) from Vietnam, with proposal of new subgroups in the B. fungivorus group

Bursaphelenchus kesiyae n. sp. is described. The new species was isolated from dead wood of Pinus kesiya during a field survey of nematodes associated with dead pine trees (Pinus spp.). The new species is medium- to large-sized for the genus, with males 690-1059 μm and females 837-1122 μm in body length, and has four lateral lines, six male genital papillae (P1 ventral single papilla is missing or vestigial), a mitten-shaped spicule with clear dorsal and ventral limbs, an indistinctive small and narrow bursal flap, vulva lacking any flap apparatus, and female tail long, tapering and straight or slightly ventrally curved. Based upon its diagnostic morphological characters, the new species belongs to the B. fungivorus group and is closely related to B. thailandae and B. parathailandae, with which it forms a cryptic species complex. However, the new species is distinguished from these two species by the morphology of the male bursal flap and several morphometric values, i.e., the bursal flap of the new species is inconspicuous, or almost lost in many individuals. Molecular phylogenetic analysis inferred from near-full-length SSU and D2-D3 LSU supported the morphological observations, i.e., the new species is molecularly similar to B. thailandae and B. parathailandae, but could be distinguished phylogenetically. Further, differences in molecular sequences in SSU and D2-D3 LSU between the new species and its close relatives are slightly higher than those between B. xylophilus and B. mucronatus, thus, identification of the species status for B. kesiyae n. sp. is considered warranted.

A new species of Larimichthys from Terengganu, east coast of Peninsular Malaysia (Perciformes: Sciaenidae).

A new species of Larimichthys from Terengganu, east coast of Peninsular Malaysia is described from specimens collected from the fish landing port at Pulau Kambing, Kuala Terengganu. Larimichthys terengganui can be readily distinguished from other species of the genus by having an equally short pair of ventral limbs at the end of the gas bladder appendages, which do not extend lateral-ventrally to the lower half of the body wall, and fewer dorsal soft rays (29-32 vs. 31-36) and vertebrae (24 vs. 25-28). Larimichthys terengganui can be distinguished from L. polyactis and L. crocea by having a gill raker at the angle of first gill arch shorter than the gill filament. Furthermore, the second anal spine in L. terengganui is equal or slightly shorter than eye diameter (vs. shorter in L. polyactis); L. terengganui has 8-9 anal soft rays (vs. only 7 in L. pamoides). Snout length of L. terengganui is greater than eye diameter, whereas in L. crocea the snout is shorter than eye diameter. A key to species of Larimichthys is provided. All obtained specimens of the species were recorded from Terengganu waters, east coast of Peninsular Malaysia.

Description of Ruehmaphelenchus juliae n. sp. (Tylenchina: Aphelenchoididae) isolated from an ambrosia beetle, Xylosandrus crassiusculus (Motschulsky), from South Florida

During a survey of nematode associates of ambrosia beetles from dead and dying red bay and avocado trees affected by the laurel wilt epidemic in southern Florida, a Ruehmaphelenchus species was isolated from the non-native ambrosia beetle, Xylosandrus crassiusculus. The new species is characterised by its possession of an oral disc at the stoma opening, three lines in the lateral field, male spicule with clear dorsal and ventral limbs connected by elongated triangular cuticle, thin membrane-like tissue and cuticular bridge-like structure, conical tail with pointed tip of males and conical tail with digitate mucro of females. The new species is very similar to four previously described species: R. asiaticus, R. digitulus, R. thailandae and R. sirisus, and can be distinguished only by some minor morphological differences in male tail characters, i.e., spicule morphology, position of genital papillae and tail tip shape, and morphometric values. However, the new species is phylogenetically unique, i.e., it is the basal taxon of the Ruehmaphelenchus clade and close to Bursaphelenchus spp. Ruehmaphelenchus juliae n. sp. is therefore proposed based on its morphological diagnostic characters and molecular sequences of near-full-length of SSU, internal transcribed spacer region, D1, D2 and D3 expansion segments of LSU ribosomal RNA and partial mitochondrial COI genes.

Precaval Right Renal Arteries with Circum-aortic Left Renal Vein.

Sir, I have read with interest, the article which is entitled, “A Right Ectopic Kidney with Bilateral Multiple Anomalies of the Renal vasculature – A Case Report” by Krishnaveni C and Roopa Kulkarni, which appeared in the year 2013, Volume 7, Issue 1, pages 150-153 of your journal [1]. The authors have described a case of unilateral right renal ectopia with bilateral multiple renal arteries, 5 on the right side and 2 on the left side. The renal veins were 3 on the right side and 2 on the left side, with retroaortic left renal vein in a male cadaver and their observations were supported with good photographs. I wish to draw the attention of readers to the following additional variations which were observed, which have not caught the attention of the authors, probably due to lack of awareness of such variations. The authors have reported the presence of 5 renal arteries which supplied an ectopic right kidney, with the hilum facing anteriorly. Though the authors described the origins of all five right renal arteries, they did not mention the abnormal course of all five arteries which passed anterior to inferior vena cava, to reach the renal hilum. This course is clearly seen in the [Table/Fig-1] which was published. [Table/Fig-1]: Right renal arteries (RRA1 – RRA4) having a precaval course crossing anterior to IVC are marked * Normally, right renal artery passes posterior to inferior vena cava to reach the renal hilum, but right renal arteries which have an anomalous anterior course are referred to as precaval right renal arteries. The incidence of precaval right renal arteries which has been reported in the literature variesfrom 5.0%- 9.17% [2–4]. Rameshbabu et al in a MDCT angiographic study, reported a prevalence of 8.88 % [5]. A majority of precaval right renal arteries are accessory inferior polar or accessory hilar arteries. All right renal arteries, main and accessory, which have a precaval course are very rare. Precaval right renal artery may be one of the causes of obstruction of ureteropelvic junction, which causes hydronephrosis and clinical symptoms and may be injured in endopyelotomy procedures and may be confused with other vessels such as mesenteric or gonadal arteries during laparoscopic and other surgical procedures. Though much attention has been paid to the numerical variations and prehilar branching patterns of the renal arteries, anomalous precaval course of the right renal artery has drawn very little attention and it has been reported only sporadically in the literature. The authors have also reported the presence of two left renal veins, one main (LRV 1) and the other, accessory renal vein (Acc RV) as seen in [Table/Fig-2]. The accessory left renal vein extended behind the aorta as the retro-aortic renal vein and it drained into the inferior vena cava. In discussion, the authors have given the embryological explanation that the persistence of the posteriorm part of the renal collar gave rise to the retro-aortic renal vein. But the authors have failed to emphasize that the main left renal vein had a normal preaortic course which crossed anterior to aorta, just below the level of origin of superior mesenteric artery. Presence of two left renal veins, one passing anterior and another posterior to aorta, is called as circumaortic left renal vein or renal venous collar, whatever the level of crossing is, but the authors have not mentioned it. This developmental anomaly occurs due to the persistence of both ventral and dorsal limbs of intersubcardinal anastomosis around the dorsal aorta. Normally, the ventral limb persists as the left renal vein and the dorsal limb disappears. Persistence of the dorsal limb alone gives rise to retroaortic left renal vein. Approximate prevalence of circumaortic left renal vein is 0.3 – 3.7 % [6]. Aljabri et al., [7], after analyzing 1788 cases reported a prevalence of circumaortic left renal vein in 1.62 %. cases and emphasized the importance of left renal vein anomalies in aortoiliac surgeries. The retroaortic segment may be compressed between aorta and vertebral column, resulting in posterior nutcracker phenomenon. This case report under discussion, actually depicts the presence of circumaortic left renal vein, associated with multiple precaval right renal arteries supplying an ectopic malrotated right kidney. Knowledge on the variations is very important for proper appreciation of them. I have tried to add some observations for the benefit of the readers. The suggested references may enrich the knowledge of readers about the renal vascular anomalies and their clinical importance.Thanks to the authors and the journal for publishing such a rare association of renal anomalies, which was supported by excellent photographs, which clearly depicted the vascular anomalies. [Table/Fig-2]: Circumaortic left renal vein with the Main Left renal vein (LRV) having a normal preaortic course and an accessory LRV having a retroaortic course are marked *

Bursaphelenchus posterovulvus sp. n. (Nematoda: Parasitaphelenchidae) in packaging wood from Singapore

Bursaphelenchus posterovulvussp. n., isolated in Ningbo, P.R. China, from non-coniferous packaging wood from Singapore is described. It is characterised by a slim body (a = 24-43), lip region strongly offset, stylet with prominent and strongly sclerotised basal swellings, lateral field with four lines, excretory pore located at level of median bulb, hemizonid 30-40 μm posterior to excretory pore, vulva at 82-86% of total body length, post-uterine branch extending forcatwo-thirds of vulva-anus distance, female tail conical and short (c′ = 2.3-3.0) with a pointed terminus, spicules short (11-16 μm) and slightly arcuate, rostrum blunt and relatively short, dorsal and ventral limbs conspicuous and their distal ends separated, three pairs of ventro-sublateral papillae and a single precloacal papilla. The new species is distinguished from otherBursaphelenchusspecies by morphology, ITS-RFLP patterns and phylogenetic analyses.

Description of Ruehmaphelenchus formosanus n. sp. (Tylenchina: Aphelenchoididae) isolated from Euwallacea fornicates from Taiwan

A Ruehmaphelenchus species was isolated from an ambrosia beetle, Euwallacea fornicates, during a biodiversity survey of entomophilic nematodes in Taichung, Taiwan. The new species is characterised by a unique tail morphology in both males and females, and a unique spicule morphology in males. The male spicule has clear dorsal and ventral limbs (connected by a blade-like cuticle), a triangular membrane-like structure on its sides, and short, conspicuous, laterally oriented, projections at the distal end. In a molecular phylogenetic tree, inferred from near-full-length small subunit (SSU: 18S) and D2/D3 expansion segments of the large subunit (LSU: 28S) of ribosomal RNA, the new species and other nominal and undescribed Ruehmaphelenchus species formed a well supported clade within Bursaphelenchus. Although this result supports a previous study that suggested that Ruehmaphelenchus is a junior synonym of Bursaphelenchus, the generic relationship between Ruehmaphelenchus and Bursaphelenchus remains somewhat uncertain. Therefore, R. formosanus n. sp. is described as a member of Ruehmaphelenchus, although this should be regarded as a tentative placement.

Bursaphelenchus tadamiensis n. sp. (Nematoda: Aphelenchoididae), isolated from a stag beetle, Dorcus striatipennis (Coleoptera: Lucanidae), from Japan

Bursaphelenchus tadamiensis n. sp. is described. The new species was isolated during a field survey of nematodes associated with stag beetles. It was recovered from the dissected body of a Dorcus striatipennis, from Tadami, Fukushima, Japan. The new species is medium sized for the genus, with males 486-772 μm and females 643-997 μm in body length, and has four lateral lines, six male genital papillae (P1 ventral single papilla is missing or vestigial), mitten-shaped spicule with clear dorsal and ventral limbs, rather large squared bursal flap, vulva lacking flap, female tail long, tapering and ventrally curved. Based upon its diagnostic morphological characters, the new species belongs to the B. fungivorus group and is close to B. thailandae, B. willibaldi and B. braaschae. It is distinguished from these three species by morphology of the male bursal flap and several morphometric values, e.g., the V value of B. tadamiensis n. sp. is clearly larger than that of the above three species. The molecular phylogenetic analyses inferred from near full-length SSU and D2/D3 LSU supported the morphological observations, i.e., the new species is molecularly similar to B. thailandae, B. willibaldi, B. braaschae and B. kiyoharai. The stag beetle association of the new species may be an accidental phoresy, although the nematode could be undergoing carrier (vector) switching, because only two adult (no dauer juveniles) individuals were isolated from only one of 100 beetles examined. The insect organ with which the nematode was associated is unknown.

Oncolytic Adenovirus Expressing Soluble TGFβ Receptor II-Fc-mediated Inhibition of Established Bone Metastases: A Safe and Effective Systemic Therapeutic Approach for Breast Cancer

In recent years, oncolytic adenoviruses have shown some promise as a novel class of antitumor agents. However, their utility in targeting bone metastases is relatively less studied. We have examined whether the systemic therapy of oncolytic adenoviruses expressing the soluble form of transforming growth factor-β (TGFβ) receptor II fused with human immunoglobulin G1 can be developed for the treatment of established breast cancer bone metastases. MDA-MB-231-luc2 human breast cancer cells were injected in the left heart ventricle of nude mice to establish bone metastasis. Mice with hind limb tumors were administered (on days 8 and 11) oncolytic adenoviruses-Ad.sTβRFc or mhTERTAd.sTβRFc. Skeletal tumor growth was monitored weekly by bioluminescence imaging (BLI) and radiography. At the termination time on day 28, hind limb bones were analyzed for tumor burden, synchrotron micro-computed tomography, and osteoclast activation. Intravenous delivery of Ad.sTβRFc and mhTERTAd.sTβRFc induced significant inhibition of tumor growth, reduction of tumor burden, osteoclast activation, and increased animals' survival. Oncolytic adenoviruses were safer than dl309, a wild-type virus. A slight elevation of liver enzyme activity was observed after Ad.sTβRFc administration; this subsided with time. Based on these studies, we believe that Ad.sTβRFc and mhTERTAd.sTβRFc can be developed as a safe and effective approach for the treatment of established bone metastasis.

Comparative morphology of the somatic musculature in species of Hexarthra and Polyarthra (Rotifera, Monogononta): Its function in appendage movement and escape behavior

Species of Hexarthra and Polyarthra are freshwater rotifers with well-known escape behaviors that result from interactions with planktonic predators. Both rotifers bear a suite of mobile appendages that function in evasive maneuvers and saltatory jumps through the water column, but the anatomical and functional bases of these actions are poorly understood. Here, we use a combination of phalloidin staining, confocal laser scanning microscopy, and video analysis to describe the morphology of the somatic muscles that supply the mobile appendages in order to understand how they function in escape behavior. Results show that species of Hexarthra, which bear six radially distributed limbs, possess a highly complex trunk musculature that supplies the inside of each limb with its own abductor and adductor muscles, i.e., a direct muscle supply. The singular dorsal and ventral limbs each receive a pair of large abductor and adductor muscles (four muscles total per limb), while the paired dorsolateral and ventrolateral limbs each receives three muscles (two abductors, one adductor per limb). Contraction of the abductor muscles creates a power stroke in the form of an anterior sweep of the limbs, which leads to a three-dimensional tumbling of the rotifer through the water column. Alternatively, species of Polyarthra possess 12 blade-like appendages that are arranged into four equal bundles; each bundle receives an indirect muscle supply that attaches to the shoulder of the paddles. A single longitudinal paddle muscle supplies each dorsolateral bundle, while a pair of longitudinal paddle muscles supplies each ventrolateral bundle. Contraction of these muscles, whether singly or in concert, functions to abduct the paddles in a power stroke, leading to rotation of the body and movement of the rotifer. The recovery stroke is hypothesized to be a multi-step process that begins with reorientation of the appendages prior to adduction, followed by contraction of various muscles to antagonize the paddle muscles. In total, these observations reveal novel complexities in the rotifer muscular system that aids our understanding of the biophysics of predator avoidance in appendage-bearing rotifers.

Prevalence and body distribution of sarcoids in South African Cape mountain zebra (Equus zebra zebra)

There are no reports in the literature describing any tumours, and specifically sarcoids, in zebras. The equine sarcoid, a locally aggressive, fibroblastic skin tumour, is the most common dermatological neoplasm reported in horses. The Cape mountain zebra (CMZ) has been described as one of the most vulnerable mammals in South Africa with current populations existing in isolated units. All South African CMZ are descendants from no more than 30 individual animals originating from 3 populations, namely the Mountain Zebra National Park, and Kammanassie and Gamka Mountain Nature Reserves near Cradock. The possibility therefore exists that the existing populations arose from a very small gene pool and that they are considerably inbred. A reduction in major histocompatibility complex diversity due to genetic bottlenecks and subsequent inbreeding probably contributed to uniform population sensitivity and the subsequent development of sarcoid in two CMZ populations, namely in the Bontebok National Park and Gariep Nature Reserve. The entire population of CMZ in the Bontebok National Park was observed and sampled during 2002 to document the prevalence and body distribution of sarcoids. During the same year, a comparative study was carried out on an outbred population of Burchell's zebra in the Kruger National Park. The prevalence in CMZ in the Bontebok National Park was 53 %, while the Burchell's zebra in Kruger National Park had a prevalence of 1.9 %. The most common sites for sarcoid in CMZ were the ventral abdomen and limbs. Prevalence of sarcoids in horses recorded in the literature varies between 0.5 % and 2 %. The Gariep Nature Reserve recently reported a prevalence of almost 25 % in CMZ in the reserve.

Epibionts of Sympatric Species of Cancer Crabs in Barkley Sound, British Columbia

The diversity, abundance and spatial distribution of macro-epibionts colonizing the graceful crab, Cancer gracilis, the red rock crab, Cancer productus, and the Dungeness crab Cancer magister were examined. These three crab species were common in Barkley Sound, British Columbia, occurring sympatrically across much of their range. Twenty nine epibiont species, representing ten different phyla were found. Thirty three percent of Cancer gracilis, 49% of Cancer magister and 68% of Cancer productus possessed one or more epibiont species. Cancer gracilis was the least speciose, while Cancer productus exhibited the greatest diversity of epibiont species. Male crabs were larger than females and had a greater species richness and diversity of epibionts. Epibionts were largely absent on juvenile crabs; in adult crabs, occurrence increased with crab size. Barnacles were the most common epibiont; the majority were Balanus crenatus, which predominated on the dorsal surfaces of the cephalothorax of each crab species. Green, red and brown algae were also common, the majority of which (.80%) were found on the antennae of the crabs. Tube-dwelling polychaete worms were less abundant, showing a preference for the ventral surfaces of the crabs. Hydrozoan colonies were found on only 7% of all the crabs examined, mostly settling on the ventral surfaces and limbs. Bryozoans were only found on Cancer productus and Cancer magister. The majority were the encrusting Membranipora membranacea. Unlike the above taxa, bryozoans showed no clear preference for a specific area of the carapace. Organisms in the phyla Urochordata, Mollusca and Porifera were only found on a few individual Cancer magister and Cancer productus. The distribution of each epibiont species is discussed in relation to larval settlement patterns and ecological, morphological and behavioural differences among the three host species.

Canine keratinocyte culture and use of a cultured epidermal autograft in a dog

SummaryA seven month old female Yorkshire Terrier was admitted with severe contracture and scarring of the ventral abdomen, thorax and limbs, after a scald injury. Surgical management consisted of multiple releasing and reconstruction skin flaps. Keratinocytes, harvested from a 1 cm2 full thickness skin biopsy, were cultured on a lawn of irradiated feeder cells, and used as a cultured epithelial autograft on the remaining skin deficits. Epithelialisation of the deficits was complete at the first dressing change, five days after application. This is the first report of successful culture of canine keratinocytes suitable for use in skin reconstruction in a clinical case.

Activations related to “mirror” and “canonical” neurones in the human brain: an fMRI study

In the macaque monkey ventral premotor cortex (F5), “canonical neurones” are active when the monkey observes an object and when the monkey grasps that object. In the same area, “mirror neurones” fire both when the monkey observes another monkey grasping an object and when the monkey grasps that object. We used event-related fMRI to investigate where in the human brain activation can be found that reflects both canonical and mirror neuronal activity. There was activation in the intraparietal and ventral limbs of the precentral sulcus when subjects observed objects and when they executed movements in response to the objects (canonical neurones). There was activation in the dorsal premotor cortex, the intraparietal cortex, the parietal operculum (SII), and the superior temporal sulcus when subjects observed gestures (mirror neurones). Finally, activations in the ventral premotor cortex and inferior frontal gyrus (area 44) were found when subjects imitated gestures and executed movements in response to objects. We suggest that in the human brain, the ventral limb of the precentral sulcus may form part of the area designated F5 in the macaque monkey. It is possible that area 44 forms an anterior part of F5, though anatomical studies suggest that it may be a transitional area between the premotor and prefrontal cortices.

CDNA Cloning of a Murine Homologue ofDrosophilaSingle-Minded, Its mRNA Expression in Mouse Development, and Chromosome Localization

A combination of the RT-PCR method and subsequent screening of the cDNA library of mouse skeletal muscle with the cDNA isolated by RT-PCR used as a probe led to isolation of cDNAs encoding a polypeptide (mSim) with bHLH and PAS domains which show high similarity to the corresponding regions ofDrosophilaSim, a master regulator in neurogenesis. Experiments using a GST-fusion protein demonstrated that mSim heterodimerizes with Arnt (Ah receptor nuclear translocator), even more efficiently than AhR (Ah receptor) does with Arnt. RNA blot analysis using RNAs from various tissues of mice indicated that mSim transcript is expressed in several limited tissues such as muscle, kidney and lung of adult animals. Distribution of mSim mRNA was always accompanied with that of Arnt. All the results suggest a regulatory role of mSim in partnership with Arnt. Chromosomal location of the mSim gene was determined by fluorescentin situhybridization to be localized on the C3.3–C4 band of mouse chromosome 16 which is syntenic with the human chromosome 21q22 carrying the Down syndrome critical region, where a gene highly homologous to theDrosophila simwas localized. Whole mountin situhybridization using a unique part of mSim cDNA sequence showed that mSim mRNA was expressed in the ventral diencephalon, branchial arches and limbs. These findings will provide an approach to the cause of the Down syndrome as well as the elucidation of the functional roles of mSim in animal development.