-
[show abstract]
[hide abstract]
ABSTRACT: Sexual dimorphism in the craniomandibular traits in the Korean water deer Hydropotes inermis argyropus was examined for the first time. Multivariate analyses using only cranial traits showed a clear separation between sexes. However, the separation was not obvious in the discriminant analysis using only mandibular traits. The most clearly dimorphic trait was in the incisive bone breadth, which was about 12% larger in males. The incisive bone width reflects the characteristically large canines in male. In contrast to this, most of the cranial measurements, except for the incisive breadth, were larger in female, indicating a larger overall skull size. Given that males are generally larger than females, this sexually dimorphic pattern is unique among mammals. We propose that factors, for example, a unique parental care, have influenced the larger skull size in the females of this species.
Journal of Veterinary Medical Science 04/2013; · 0.85 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In order to gather basic reproductive information of the water deer and Reeves' muntjac, the immunolocalization of the cytoskeleton proteins in the testes and epididymides of these two species were investigated. The distribution pattern of cytoskeletal proteins in these two species was similar. The desmin was detected in the peritubular myoid cells of the testes and the sub-epithelial cells of the epididymal ducts. Vimentin was observed in the myoid cells, Leydig cells and perinuclear region of the Sertoli cells. Intense immunoreactions for α-smooth muscle actin were restricted to the smooth vascular muscle cells and the peritubular myoid cells in the testes. From the present results, it appears that these distribution patterns of cytoskeletal proteins may be common in the cervids.
Journal of Veterinary Medical Science 03/2013; · 0.85 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: ABSTRAcT. We examined sexual dimorphism in the craniodental traits of the raccoon dog Nyctereutes procyonoides from South Korea. Univariate comparisons of skull (cranium and mandible) and dental measurements revealed a small extent of sexual dimorphism in some measurements. The most indicative dimorphic measurements were the breadths of the upper and lower canines which were around 8% larger in male specimens on average. On the other hand, multivariate analyses using only skull traits showed slightly a clearer separation between sexes than those using only dental ones. This discrepancy may be derived from a higher variability in dental traits than in those of the skull. In conclusion, sexual dimorphism within N. procyonoides of South Korea is present, but was not so pronounced as for other local populations. However, measurements showing significant sexual dimorphism varied between different localities. This suggests that the selective forces acting upon craniodental morphology of each sex vary between populations of the species. KEY WORDS: craniodental morphology, Nyctereutes procyonoides koreensis, raccoon dog, sexual dimorphism.
-
[show abstract]
[hide abstract]
ABSTRACT: We examined sexual dimorphism in the craniodental traits of the raccoon dog Nyctereutes procyonoides from South Korea. Univariate comparisons of skull (cranium and mandible) and dental measurements revealed a small extent of sexual dimorphism in some measurements. The most indicative dimorphic measurements were the breadths of the upper and lower canines which were around 8% larger in male specimens on average. On the other hand, multivariate analyses using only skull traits showed slightly a clearer separation between sexes than those using only dental ones. This discrepancy may be derived from a higher variability in dental traits than in those of the skull. In conclusion, sexual dimorphism within N. procyonoides of South Korea is present, but was not so pronounced as for other local populations. However, measurements showing significant sexual dimorphism varied between different localities. This suggests that the selective forces acting upon craniodental morphology of each sex vary between populations of the species.
Journal of Veterinary Medical Science 08/2012; · 0.85 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Tragulidae is a primitive ungulate family within the order Cetartiodactyla, suborder Ruminantia. Domestic ruminants such as cattle, sheep, and goat have two types of Peyer's patches (PP): jejunal and ileal PP, in which there are morphological and functional differences. In this study, lesser mouse deer (Tragulus javanicus) PP was studied by gross anatomical and histological procedures. At the fetal stage, both types of PP were formed in the small intestine. Ileal PP was observed as a single continuous aggregation of lymphatic follicles extending cranially from the ileo-caecal junction. However, jejunal PP was observed as multiple and discrete accumulations of lymphatic follicles. This study showed that the lesser mouse deer has two types of PP in the small intestine. In addition, the anatomical and histological characteristics of jejunal and ileal PP are quite similar to those of other ruminants' jejunal and ileal PP. Further studies are needed to analyze immune function of both PP in lesser mouse deer in order to determine the evolutionary process of Cetartiodactyla.
Veterinary Immunology and Immunopathology 05/2012; 149(1-2):103-7. · 2.08 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This study aimed at demonstrating the profiles of circulating gonadal steroid hormones during the estrous cycle and pregnancy in a southern tamandua (Tamandua tetradactyla). Additionally, this study clarified the relationship between vulvar bleeding and hormonal changes. The concentrations of serum progesterone (P(4)) and estradiol-17β (E(2)) were determined by enzyme immunoassays. Serum P(4) and E(2) concentrations changed cyclically and the estrous cycle length (± SD) based on the E(2) cycles was 44.3 ± 4.5 days. Vulvar bleeding started to be seen at the decreasing of P(4). The cycle length for vulvar bleeding was 43.3 ± 4.2 days. Interval from the first day of bleeding to the peak of E(2) concentration was 23.1 ± 3.1 days. Serum P(4) during pregnancy remained high and E(2) increased 8 weeks after conception and remained high until parturition. The female delivered normally after a 165 day-pregnancy period and reared the offspring well. Approximately 3 weeks after parturition, serum E(2) and P(4) cycles resumed. Visual bleeding may be useful as a real-time indicator for understanding the ovarian cycle of southern tamanduas, and estrus could be expected approximately 3 weeks after the first bleeding.
Zoo Biology 03/2011; 30(2):212-7. · 0.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The streaked tenrec (Hemicentetes semispinosus) is equipped with a quill vibrating mechanism on the dorsal side of the caudal trunk that has evolved as an extraordinary sounding apparatus for communication. An arrangement of 15 or 16 light-brown quills was observed. Thickened cutaneous muscles were confirmed beneath quills. We named this structure the "quill vibrator disc" (QVD). The QVD was 16.8 mm long and 8.55 mm wide in a typical adult. Longitudinal musculature symmetrical about the sagittal plane was developed in the QVD. Myocytes were found immunohistochemically to contain mainly fast myosin but not slow myosin. These findings indicate that the QVD is a specialized apparatus in the cutaneous muscle that contributes to the vibration of quills and to the production of sound for communication.
ZOOLOGICAL SCIENCE 05/2010; 27(5):427-32. · 0.95 Impact Factor
-
Mammal Study 04/2010; · 0.58 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The jungle crow (Corvus macrorhynchos) distribution stretches from eastern Eurasia continent to southeastern Asia. The distribution of the black-billed magpie (Pica pica sericea) stretches from Korea and China to the Kyushu area in Japan. They are both in the Family, Corvidae, and have iridescent feather colors, but the iridescent feather color of the black-billed magpie is more remarkable than that of the jungle crow. We observed the feather microstructure of these birds using electron microscope. On the barbules surface, the barbules twist and prong between the jungle crow and black-billed magpie were not similar. In the barbules cross section, the black-billed magpie showed a complex structure of melanin granules, the jungle crow showed a simple structure of melanin granules.
Journal of Veterinary Medical Science 03/2010; 72(8):1047-50. · 0.85 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This study demonstrated the immunohistochemical localization of cytoskeletal proteins, cytokeratin, desmin, vimentin, α-tubulin and α-smooth muscle actin (α-SMA) in the testes of adult and immature lesser mouse deer (Tragulus javanicus). Desmin was found in the sub-epithelial myoid cells of epididymal ducts. The immunoreactivity for vimentin was shown in the peritubular myoid cells and around the nuclei of the Sertoli cells of which the positions indicated various arrangements. In the Sertoli cells, vimentin filaments between the basement membrane and the nucleus were elongated with the migration of the nucleus toward the upper part. Furthermore, vimentin was detected in the Leydig cells and the sub-epithelial myoid cells of epididymal ducts. Alpha-tubulin was apparently extended to the tip of each Sertoli cell cytoplasm, and α-SMA was found in the peritubular myoid cells and the sub-epithelial myoid cells of epididymal ducts. On the other hand, cytokeratin and desmin were not detected in the Sertoli cells, Leydig cells, spermatogenic cells and peritubular myoid cells. In the mouse deer testes, vimentin filaments of the Sertoli cells may not be involved in the migration of the elongated spermatids and spermiation like as rat Sertoli cells because the supranuclear extension of vimentin was scanty.
Mammal Study 03/2010; 35(1):57-64. · 0.58 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The presacral vertebra of anteaters was examined by three-dimensional CT image analysis of the xenarthrous processes peculiar to the Order Xenarthra. The anteater is equipped with two following articulations in addition to the normal zygapophysial articulation. The dorsal xenarthrous process of the former vertebra articulates to the ventral area of the base of the mammillary process in the later vertebra. The pocket-like structure in the ventral area of the mammillary process receives the dorsal and ventral xenarthrous processes of the former vertebra. The complicated articulations do not obstruct the ability of the giant anteater to flex dorsally and laterally, however aids flexibility and strengthens the caudal thoracic and lumber regions of the animal. The xenarthrous processes and articulations may function as a supporter of the body weight during the bipedal standing posture when the anteater destroys the nests of ants and termites and protects itself from the enemies.
Mammal Study 04/2009; · 0.58 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The heart structure of the Asian elephant (Elephas maximus) was observed by macroscopic and CT scanning methods. The heart was 8,230 and 9,640 g in weight, 480 and 550 mm in length in the two examined elephants, respectively. In the right ventricle, the papillary muscles in the interventricular septum were identified as M. papillaris subarteriosus et parvus, whereas in the ventricular wall as M. papillaris magnus. The Chordae tendineae from the M. papillaris subarteriosus et parvus reached the margin of the Cuspis angularis, whereas the Chordae tendineae from the M. papillaris magnus supported the Cuspis septalis of the right atrioventricular valve. In the Cuspis parietalis area, the Chordae tendineae connected this valve with the M. papillaris magnus. The left atrioventricular (bicuspid) valve consisted of Cuspis septalis and the Cuspis parietalis, that the Chordae tendineae reached from M. papillaris subauricularis et subatrialis. From the CT sections, we demonstrated that the left ventricular wall was 50–60 mm in left lateral side of the ventricular wall, whereas the right ventricular wall appeared 15–25 mm in thickness. The atria possessed the wall of 15–30 mm in thickness. In the Asian elephant the heart certainly requires a large volume and a thick ventricular wall, however, the muscular wall is not equipped with the highly-functioned structure adapted to its large body size.
Mammal Study 01/2009; · 0.58 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: CT scanning and its related three-dimensional image techniques were applied for a carcass head of a newborn Indian rhinoceros (Rhinoceros unicornis) to clarify if the guttural pouch is well-developed or not in the early growth stages of this species. Observations from the sections of the CT three-dimensional reconstructed image reveal that the guttural pouch is not present around the stylohyoid bone in a new born Indian rhinoceros. Since the absence of the guttural pouch has been confirmed also in adult rhinoceros, we can point out that the guttural pouch does not disappear during the growth stages, but is originally absent in the newborn. Although the well-developed guttural pouch in the horse and ass has attracted anatomists, we can conclude that the guttural pouch is not commonly observed in the perissodactyls, but in a few species of Equus, and that the guttural pouch is adapted only to restricted roles in the smaller taxa within perissodactyls.
Mammal Study 01/2009; 34:7-11. · 0.58 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The gross anatomy of the mastication system of the giant anteater (Myrmecophaga tridactyla) was examined by means of three-dimensional image analysis. The anteater rotates the mandibles medially and laterally to control its tongue when it is elongated and to house it when it is relaxed. Three-dimensional CT image analysis demonstrated that the shape and size of the oral cavity changes drastically when the mandibles are rotated. The oral cavity expands bilaterally when the dorsal part of the mandibles bend medially. Macroscopic observations and muscle-weight data supported the observation that the superficial temporal and medial pterygoid muscles act as the main medial and lateral rotators of the mandible, respectively. The low height of the mandibular ramus and the incomplete zygomatic arch in this species represent adaptations for the rotational movement of the mandibles, since they both contribute to the medially oriented transmission of force from the temporal muscles and to preventing collision between the mandibles and the cranium during the rotational movement.
ZOOLOGICAL SCIENCE 11/2007; 24(10):1005-11. · 0.95 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The manipulating action of the lesser panda (Ailurus fulgens) was quantitatively analyzed by the CT and three-dimensional digitalized techniques. The forearm, metacarpals, radial sesamoid bone and accessory carpal bone were considered as movable parts in the simulation of the dead body, and we examined the change of angles among these four segments in the grasping action. In the manipulation the radial sesamoid bone moved independently from the metacarpals in the lesser panda. It was not articulated to the first metacarpal bone, but supported by some muscle tendons and the other soft parts of the wrist and palm regions. Although the grasping apparatus consists of the functional units of the radial sesamoid bone and accessory carpal bone in the giant panda (Aliluropoda melanoleuca), the manipulating mechanism using the radial sesamoid bone in the lesser panda had no functional-morphological similarities to that in the giant panda. The radial sesamoid bone as a manipulating tool of the lesser panda has been developed in the separated evolutionary history of this species.
Mammal Study 05/2007; · 0.58 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The geographical variation of the gray-bellied squirrel (Callosciurus caniceps) was examined using osteometry of skull in Southeast Asia. From the principal component analysis (PCA), the plots of the northern localities from Nan to Kanchanaburi and those of the southern localities from Narathiwat to Kuala Lumpur in male were completely separated. In female, the plots of the locality from Uttradit to Kanchanaburi and those of the locality from Pattani to Negri Sembilan were completely separated. We called these northern localities and southern localities which are distinguished by the PCA as N group and S group. The size and shape of the skulls of these squirrels indicated the differences between N group and S group from t-test and U-test. These results may be influenced by the two transitions of the phytogeography around the southernmost locality in N group and the northernmost locality in S group in the peninsular Thailand and Malay Peninsula. Localities which are located between N and S groups were called the Middle (M) group. From the PCA among N, S groups and each locality of M group, the plots of localities such as Prachuap Khiri Khan, Chumphon, Krabi, Nakhon Si Thammarat and Trang in both sexes of M group could not be separated from those of N and S groups. We suggest that the sympatric distribution of N and S groups and the hybrid of N and S populations may be seen in these localities of M group.
Journal of Veterinary Medical Science 03/2007; 69(2):149-57. · 0.85 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The intracranial carotid rete (or rete mirabile epidurale) is a unique blood vascular system supplying the brain of artiodactyls, which have either an involuted or no internal carotid artery. Although the lesser and greater mouse deer (Tragulus javanicus and T. napu, respectively) are ruminants, the rete mirabile epidurale is absent. In these animals, as in non-artiodactyls, such as canines, equines and humans, the complete internal carotid artery supplies the brain. It is currently uncertain whether the absence of the rete is confined to mouse deer among ruminants. The absence of the rete in mouse deer provides new insights into the evolution of the arterial system in artiodactyls.
Journal of Anatomy 02/2007; 210(1):112-6. · 2.37 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We observed the muscles of hindlimb, talus, and tarsal joints in the lesser mouse deer (Tragulus javanicus) and greater mouse deer (Tragulus napu) that have conserved the original morphological characters of the musculoskeletal system in the Ruminantia. The proximal trochlea articulating to the distal end of the tibia obviously turned at a medio-proximal direction. Since the proximal parts of the muscle bundles were concentrated in the lateral side of the thigh, the tension of the extensor muscles in the hindlimb is mediodistally conducted. It indicates that the extending power of hindlimb muscles is not parallel with the direction of the trochlea, but crosses the angle of the proximal pulleys in the talus. We suggest that the crossing may enable the animal to stand and run stably and to bear its body weight. We compared the development of the hindlimb muscles in the mouse deer (Tragulus javanicus and Tragulus napu) with that in the Sika deer (Cervus nippon) and Chinese muntjac (Muntiacus reevesi). The dry weight of the muscles in the mouse deer indicated that the mass of the muscles were obviously concentrated in the lateral side of the proximal area and in the cranial side in the distal area in comparison with the two other large-bodied species. We can conclude that the present findings of the hindlimb muscles and talus in the mouse deer indicate the original functional strategy of the locomotion in non-specialized species of the Suborder Ruminantia.
Mammal Study 11/2006; · 0.58 Impact Factor
-
Shintaro Iwashita,
Sadao Ueno,
Kentaro Nakashima,
Si-Young Song,
Kenshiro Ohshima,
Kazuaki Tanaka,
Hideki Endo, Junpei Kimura,
Masamichi Kurohmaru,
Katsuhiro Fukuta,
Lior David,
Naoki Osada
[show abstract]
[hide abstract]
ABSTRACT: Retrotransposable element-1 (RTE-1) is a class of long interspersed nucleotide elements that contain in its open reading frame an apurinic/apyrimidinic endonuclease domain (AP-END) and a reverse transcriptase domain. Ruminants have a clade-specific RTE-1 (BovB/RTE). The bovine bcnt gene (bucentaur or craniofacial developmental protein 1) has a duplicated paralog (bcntp97) in tandem that recruited an AP-END of BovB/RTE as a coding exon (RTE exon). We obtained sequence of the bcnt region from several animals and showed that other ruminants also have the bcntp97 with a conserved RTE exon while camels and pigs do not. Genomic Southern analysis showed that camels and pigs have multiple bcnt-related sequences but not BovB/RTE which bovines and lesser mouse deer have abundantly. These results indicate that the bcnt gene duplication followed by the creation of bcntp97 including recruitment of the RTE exon occurred in the ancestral ruminant about 55 MYA. The indication of time frame is supported by a phylogenetic analysis. Taken together with a result of differential tissue expression of the two bcnt paralogs, we conclude that bcntp97 was created concurrently with the early radiation of BovB/RTE in an ancestral ruminant and then acquired a novel function.
Molecular Biology and Evolution 05/2006; 23(4):798-806. · 5.55 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We examined the geographical variation of the skull size and shape of the lesser mouse deer (Tragulus javanicus) from Laos, Thailand, Peninsular Malaysia, Sumatra, Java, Borneo, Langkawi and some Islands of Tenasserim in Myanmar. Although the influence of the climatic condition on skull size was not confirmed in the mainland populations, the skull became rostro-caudally longer in the populations of Tenasserim and Sumatra because of island isolation effect. The skull size was classified into the following three clusters of localities from the matrix of Q-mode correlation coefficients: 1) Langkawi and Tenasserim, 2) Laos and Thailand, 3) Sumatra and Borneo. The skulls in the population of Java belong to the cluster of Langkawi and Tenasserim in male, however were morphologically similar to those in the cluster of Borneo and Sumatra. The canonical discriminant analysis pointed out that the Laos and Tenasserim populations were separated from the other ones and that the populations of Sumatra, Java and Borneo were intermingled each other.
Journal of Veterinary Medical Science 11/2004; 66(10):1229-35. · 0.85 Impact Factor
