• Applied Microscopy
• /
• v.42 no.4
• /
• pp.186-193
• /
• 2012

The ultrastructure of the secretory granules of the submandibular gland was examined in the Korean spider shrew, Sorex caecutiens, lesser white-toothed shrew, Crocidura suaveolens and big white-toothed shrew, C. lasiura. The mucous and serous acinar granules of S. caecutiens with a border of the lucid corona differed from those of C. suaveolens and C. lasiurar with a dense lateral border. The mucous acinar granules of C. lasiura with several bands producing a variety of patterns in the matrix were similar to those of C. suaveolens. The serous acinar granules of C. lasiura had a homogenous pale center surrounded by minute dense specks or had an unusual substructure showing a geometric pattern according to the inclusions in the pale matrix of the granules. This is the first report of an unusual substructure showing a geometric pattern of the serous acinar granules of C. lasiura. The myelin-like body was observed in the granular duct cell of the three species of shrew. The myelin-like body of S. caecutiens with layers of unit membranes was different from that of C. suaveolens and C. lasiura with paired membranes. Therefore, the layers composing of the paired membranes of the myelin-like body might be one of the characteristics of Crocidura.

• Journal of Life Science
• /
• v.11 no.1
• /
• pp.54-61
• /
• 2001

The comparative morphology of epididymal spermatozoa in the lesser white-toothed shrew, Crocidura suaveolens, the Japanese white-toothed shrew, C. dsinezumi and the big white-toothed shrew, C. lasiura, belonging to the subfamily Crocidurinae was studied with the light and electron microscopes. The spermatozoa of C. lasiura and C. dsinezumi were characterized by the large acrosome, serrated inner acrosomal membrane, common apical body and fistulous proximal centriole with slightly dense electron granular materials, which are the charateristics of the Crocidurinae. The C. suaveolens, however, is distinguished from the two species mentioned above in the sperm morphology. That is, the spermatozoa possess not only the charateristic of the Crocidurinae such aw the large acrosome, but also those of the Soricinae, i.e. the smooth inner acrosomal membrane, wavy, finger-like and electron-dense apical body, and the solid proximal centriole filled with electron-dense materials. The results suggest that C. suaveolens has conserved characteristics of the Soricinae.

• Applied Microscopy
• /
• v.35 no.4
• /
• pp.91-97
• /
• 2005

The acinar cells and secretory granules of the parotid salivary gland were examined in the lesser white toothed shrew, Crocidura suaveolens and the big white-toothed shrew, C. lasiura. The parotid gland of both species were a serous gland having only one kind of serous acinar cells, and had conventional arrangement of acini and intercalated, granular and striated ducts. In case of C. suaveolens, serous acinar cells had well developed rER, prominent Golgi complex, several large mitochondria and abundant moderate dense secretory granules with various stages of the maturing or fusing process. Immature acinar secretory granules were only or mainly filled with fine strong dense specks and had an indistinct limiting membrane, and mature granules were filled with homogeneous pale large round center and had fine strong dense specks at the periphery of the homogeneous pale center and a distinct limiting membrane. In case of C. lasiula, serous acinar cells had well developed rER, prominent Golgi complex, several large mitochondria and abundant dense secretory granules with maturing or fusing process. Immature acinar secretory granules were only filled with pale rough specks and had an indistinct limiting membrane, and mature granules were only filled with rough dense specks and had a distinct limiting membrane. Eventually The acinar secretory granules of C. suaveolens were seen moderate at the light and ultrastuctural level, those of C. lasiura were strong dense at the light microscopic level and dense at the ultrastructural level.

• Journal of Life Science
• /
• v.11 no.3
• /
• pp.218-229
• /
• 2001

The cycle of the seminiferous epithelium and spermiogenesis in three species if the genus Crocidura, the lesser white-toothed shrew, C. suaveolens, the Japanese white-toothed shrew, C. dsinezumi and the big(=Ussuri) white-toothed shrew C. lasiura, in the breeding season were studied with light and electron microscopes. The three species examined are distinguished from each other in the morphology of the seminiferous epithelium and the spermiogenesis, suggesting that these morphological characteristics are useful for the identification of the species. C. dsinezumi and C. lasiura, however, share many characteristics which are not common in C. suaveolens, as follows: In both species, 1) the cycle of the seminiferous epithelium is composed of 10 stages against 11 stages in C. suaveloens; 2) the earliest intermediated type spermatogonia is observed at stage I against stage III in C. suaveolens; 3) the spermatids of step 5 is observed during the stages V-VI against stages V-VII in C. suaveolens; 4) the acrosomal extension occurs during the stages VIII-X against tages IX-XI in C. suaveolens; 5) the condensation of the nucleus occurs simultaneously whereas it begins from the middle and along the nuclear membrane in C. suaveolens; 6) the capitular length in acrosome phase is shorter(about 2/3 of the diameter of the proximal centriole) than in C. suaveolens(longer than the diameter of proximal centriole; 7) length of the post nuclear cap is shorter(less than a half of the nucleus) than in C. suaveolens(about a half on the nucleus). Hudging from the similarities in the spermatogenesis in C. dsinezumi and C. lasiura, the relationship between them seems to be close compared to those with C. suaveolens.

• Applied Microscopy
• /
• v.34 no.3
• /
• pp.179-184
• /
• 2004

Normal and abnormal morphology of the epididymal spermatozoa in the big white-toothed shrew, Crocidura lasiura were studied with the light and electron microscopy. Normal spematozoa were observed with a few abnormal spermatozoa. This indicates that abnormal morphology is no absolute indicator of infertility. However, the existence of the abnormal spermatozoa is related to infertility. Especially abnormal morphology of the sperm head is definitely associated with infertility. The following types of abnormal head morphology of the epididymal spermatozoa in the wild healthy adults of the C. lasiura were described: 1) Nucleus with lack of condensation of the nucleoplasm 2) Destructed acrosome 3) Folded acrosome and plasma membrane 4) Separation of the acrosome from the nucleus 5) Acrosome with irregular condensation 6) Wrongly located granules of the apical body.

• Applied Microscopy
• /
• v.40 no.1
• /
• pp.37-45
• /
• 2010

Captured wild specimens of the big white-toothed shrew, Crocidura lasiura were classified into three age classes by tooth wear and height of molars, and seasonal variations of breeding and reproductive organs were examined. Juveniles had not tooth wear in molars and height of the third molars were lower than the first and second molars, and had only non-breeding condition. Young adults had little tooth wear and the third molars reached to the first and second molars, and old adults had heavy tooth wear in molars, young adults and old adults had breeding or non-breeding condition according to the season. On the basis of histological examination, seasonal variations of breeding were confirmed that breeding condition of young and old adult males were continued from early February to early October although the breeding activity was the highest in April, that of females were continued from the end of March to October, males reached sexual maturity earlier than females. Whereas the breeding condition seems to cease for non-breeding season because of the deficiency of food resources, soil invertebrates. Young and old adult males of the breeding season had large testes with enlarged seminiferous tubules that were filled with numerous germ cells, and expanded caudal epididymides with a vast number of spermatozoa, and were more than 10.0 g in the body weight and 0.03 g in the testis and epididymis weight. The females of the breeding season were pregnant condition with 4~6 litters or had the Graafian follicles and the corpus lutea in the ovary, and were more than 9.6 g in the body weight.

• Applied Microscopy
• /
• v.35 no.2
• /
• pp.57-64
• /
• 2005

The ultrastructure and histochemical characteristics of the submandibular gland was examined in the big white-toothed shrew, Crocidura lasiura. A submandibular gland of Crocidura lasiura was a mixed gland composed of serous and mucous acinar cells. Secretory granules from the acini were discharged through the intercalated duct, the granular duct and the striated duct into the oral cavity. Serous and mucous acinar cells and granular duct cells had large amount of rough endoplasmic reticulum, free ribosome and prominent Golgi apparatus at the basal cytoplasm of the cell, and many granules at the apical cytoplasm. Oval type serous granules had a homogeneously pale round shape of bead at the center. Mucous granules were distinct from those of the other mammalian species having variety patterns with several dense bands into homogeneous pale matrix. A serous-like secretory granules and myelin-like body were observed in the cytoplasm and the lumen of granular duct cells. The myelin-like body is a characteristic structure only reported in the salivary glands of two shrews, Suncus murinus and C. dsinezumi. Striated duct cell had numerous well-developed mitochondria but secretory granule was not shown at all.

• The Korean Journal of Zoology
• /
• v.32 no.1
• /
• pp.14-21
• /
• 1989

Four external and 22 cranial characters of 279 specimens representing 24 species of six orders of Korean mammals were measured. The data were analyzed by phenetic methods such as ordination as well as clustering techniques. Morphological distances were also calculated. Phenetic studies yield taxonomic placements of Siberian mink, Palearetic squirrel, and big white-toothed shrew which are incorrect. Morphological differences among Korean mammals at ordinal level in the taxonomic hierarchy are larger than those among other mammals: morphological differences below ordinal level are comparable to those among other mammals. Average taxonomic distances and morphological differences among Korean mammals at various levels in the taxonomic hierarchy are jointly monotonic, although the value of Pearson's product-moment correlation coefficient between average taxonomic distance matrix and morphological difference marrix is 0.59.