• Development and Reproduction
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• v.2 no.1
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• pp.101-109
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• 1998

Spermatogenesis and reproductive cycle of the razor clam, solen grandis, were investigated monthly by histological and cytological observations. Samples were collected from natural intertidal population at Oshik-do, Kunsan, Korea, for one year, beginning from January to December, 1993. solen grandis is dioecious. Morphological structures of the spermatozoon of this species ar esimilar to those of other bivalve spermatozoa having a primitive type; i.e., a small head, a cap-shaped acrosome and a short mid-piece with four mitochondria surrounding axial filament. The head of spermatozoon is approximately 2 \mu m in length and sperm tail is about 20 \mu m long. The axoneme of tail flagellum consists of nine pairs of peripheral microtubules at the periphery and a pair of central microtubules at the center. Four spherical mitochondria form the paranucleus. Spawning occures once a year between early June and July, and the main spawning was observed in July when seawater temperature reaches above 20 \circ C. The reproductive cycle of male razor clam can be divieded into fivesuccessive stages; early active (December to january), late active (January to march), mature (March to early August), partially spawned (June to July), and spent/inactive stage (August to December).

• Development and Reproduction
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• v.2 no.1
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• pp.89-99
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• 1998

This study was carried out to investigate the morphological changes of gonadotropes in pituitary gland and spermatogenic cells in testis, obtained from 150 of 3-year-old immature and mature male rainbow trout (Oncorhynchus mykiss) during the reproductive cycles from March to February in the following year. In the maturation cycle of the pituitary gonadotropes of cultured rainbow trout, three periods can be distinguished i.e. a period of resting(March-August), a period of full spermatogenesis (September-November), and a period of breeding (December-February). The ultrastructures of the gonadotropes largely parallel the cyclical changes in the tests. The seminiferous tubules contain all spermatogenetic stages and sperm cells in a period of early maturation. At first, the size of the nucleus and cytoplasm decrease gradually at every stages from spermatogonia to spermatids. In the secondary spermatocytes, the small mitochondria are located over the outer cytoplam. In spermatids, the cytoplasmic masses move toward the posterior part of the nucleus. In spermatids, the two large mitochondria are located over the cytoplasm. In spermatids, the cytoplasmic masses move towark the posterior part of the nucleus. In spermatids, the two large mitochondria are located over the cytoplasm and begin to elongate. In spermatozoa, the surface of the nucleus devreases in volume. Examination by TEM shows that the nuclear envelope and plasma membrane are slightlywrinkled and closely adhered to the nucleus of spermatozoa. Two oval mitochondria are quite separated and the flagellum is inserted into the base of the spermatozoa head.The axoneme in this fish has the typical pattern such as nine peripheral doublets and a central doublet(9+2). there are remarkable individual differences in the size and morphology of spermatozoa head as observed by transmission and scanning electron microscopy.

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.26-30
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• 2002

A bacterium isolated from contaminated white ginseng was indentified by using API kit and electron microscope. The isolate was determined as rod shaped bacterium having 0.6-1.0 ${\mu}{\textrm}{m}$ in diameter and 1.2-3.0 ${\mu}{\textrm}{m}$ in length. It had motility by flagellum. The isolate had $\beta$-galactosidase, arginine dihydrolase and omithin decarboxylase. It used citrate as sole carbon source but not produced H$_2$S. It also fermented glucose, manitol, sorbitol, rhamnose, sucrose, melibiose, arabinose and amygdalin. The isolate was identified as Enterobacter sp by the above API kit analysis and electron microscopy observation. Ginseng saponin was added to culture of Enterobacter sp. in order to investigate saponin's influence on its growth. The strain was incubated at 38$^{\circ}C$ for 3 days after addition of 0.05, 0.5, 2.0 and 4.0% (w/v) of saponin, respectively and the growth rates were investigated. The relative bacterial growth rates showed 75.0, 37.5, 7.5 and 0.5%, respectively, when compared with 100% of saponin non-added group. These results suggest that the growth of Enterobacter sp. is inhibited by saponin with the concentration dependency.

• Development and Reproduction
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• v.11 no.3
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• pp.227-233
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• 2007

The milt properties of filefish(Thamnaconus modestus) included physical properties of sperm and biochemical properties of seminal plasma. The physical properties of milt were $0.3{\pm}0.1\;mL{\cdot}fish^{-1}$ in sperm volume, $2.6{\pm}0.1{\times}10^7\;spermatozoa{\cdotg}mL^{-1}$ in sperm concentration and $73.3{\pm}6.7$ in spermatocrit. The biochemical properties of seminal plasma contained $9.8{\pm}0.9\;mmol{\cdot}L^{-1}$ potassium, $164.0{\pm}4.0\;mmol{\cdot}L^{-1}$ sodium, $151.0{\pm}1.2\;mmol{\cdot}L^{-1}$ chloride, $14.9{\pm}0.6\;mg{\cdot}dL^{-1}$ calcium, $7.2{\pm}0.1\;mg{\cdot}dL^{-1}$ magnesium, $1.0\;mg{\cdot}dL^{-1}$ glucose, $0.1\;g{\cdot}dL^{-1}$ total protein and $1.0\;mg{\cdot}dL^{-1}$ total lipid. The osmolality and pH of seminal plasma were $322.8{\pm}2.8\;mOsmol{\cdot}kg^{-1}$ and $7.7{\pm}0.1$, respectively. The spermatozoon of filefish consisted of three parts: head without acrosome, mid-piece with five mitochondria and flagellum with "9+2" pattern. The head of spermatozoon in longitudinal section was horseshoe-shaped, and $1.3{\sim}1.6\;{\mu}m$ long and $1.0{\sim}1.3\;{\mu}m$ wide.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.515-519
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• 2007

Rapid immunochromatographic assay (ICA) kits were developed using flagella-specific monoclonal antibodies (MAbs) and rabbit polyclonal antibodies for screening Listeria spp. in food. The establishment of different formats, MAb 2B1 as capture antibody and MAb 7A3 or rabbit polyclonal antibodies as detector antibody, was compared. The 2 formats of the ICA kit were shown to have specific reactions with Listeria and no cross-reactivity with any of the non-Listeria including Escherichia coli O157:H7 and Salmonella enteritidis. The detection limits of the ICA kit using the combination of gold-labeled MAb 7A3 and MAb 2B1 showed $1{\times}10^5$ and $1{\times}10^6\;CFU/0.1\;mL$ at 22 and $30^{\circ}C$, respectively. The other format of the ICA kit using the combination of gold-labeled rabbit polyclonal antibodies and MAb 2B1 showed $1{\times}10^6\;CFU/0.1\;mL$ at $22^{\circ}C$ but weak signal at 30 culture. The format utilizing MAb was more sensitive than the one using polyclonal antibodies for capture antibody. Samples contaminated with L. monocytogenes 4b culture (9-10, 5-6, and 1-2 CFU/mL) on pork and pasteurized milk were confirmed as positive results. Current data suggests that this ICA kit is a rapid, simple and effective tool to screen for Listeria spp. in food.

• Applied Microscopy
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• v.37 no.3
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• pp.185-198
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• 2007

Spermiogenesis in Japanese white-toothed shrew. Crocidura dsinezumi was investigated by transmission electron microscope. Spermiogenesis was divided into 12 phases 14 steps, based on the morphological features of the nucleus and change of organelles in cytoplasm. The nucleus of spermatids in Golgi (step $1{\sim}2$) phase were spherical; however, they were changed into oval in the cap (step $3{\sim}6$) phase. Flagellum appeared in the middle of acrosomal phase; on the other hand, slender and long spermatid head was formed in maturation phase. The head of spermatids faced the lumen in step 1 to step 6 (from Golgi to cap phase), but, in step 7 to step 14 (from acrosomal to spermiation phase), it turned its head to the basal lamina of the seminiferous epithelium. The nucleus and acrosome were elongated maximally in step 10. The condensation of chromatin started in late acrosomal (step 10) phase, and it was completely finished and homogenized in the middle of maturation (step 12) phase. Multivesicular body appeared near the acrosomal vacuole during the middle cap (step 5) phase, and a large number of them were observed near the Golgi apparatus in the late cap (step 6) phase. Considering all the results, the spermiogenesis might be useful information to analyse the differentiation of spermatogenic fells.

• Journal of Ginseng Research
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• v.32 no.3
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• pp.270-274
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• 2008

A bacterium isolated from contaminated white ginseng was identified using API kit and electron microscope. This isolate was determined as rod shaped bacterium having about 1.0 ${\mu}m$ in diameter and 2.0 to 6.0 ${\mu}m$ in length. It had motility by peritrichous flagellum. The isolate had ${\beta}-galactosidase$, arginine dihydrolase and ornithin decarboxylase. It did not have ability not only to use citrate as sole carbon source and but also to produce $H_2S$. However, it could ferment glucose, manitol, sorbitol, rhamnose, arabinose and amygdalin. From these obserbations, the isolate was identified as Citrobacter sp. Ginseng saponin was added to culture of Citrobacter sp. in order to investigate saponin's influence on its growth. The strain was incubated at $38^{\circ}C$ for 3 days after addition of 0.05, 0.5, 2.0 and 4.0% (w/v) of saponin, respectively and the growth rates was investigated. The relative bacterial growth inhibition rates showed 28.6, 66.7, 92.4 and 97.7%, respectively, when compared with saponin non-treated group. These results suggest that the growth of Citrobacter sp. is inhibited by saponin in a concentration-dependent manner.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.324-330
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• 2014

A marine bacterial strain producing agar-degrading enzymes was isolated from a mud flat in Jeboo-do (Korea) using a selective artificial sea water (ASW) agar plate containing agar as the sole carbon source. The isolate, designated as SH-1, was gram-negative, aerobic, and motile with single polar flagellum. 16S rRNA gene sequence similarity analysis showed the isolate SH-1 had the highest homology (96.5%) to marine bacterium Neiella marina J221. Cells could grow at $28-37^{\circ}C$ but not at $42^{\circ}C$, and the agarase activity of the cell culture supernatant was higher when grown at $28^{\circ}C$ than when grown at $37^{\circ}C$. Cells could grow when concentrations of 1-5% (w/v) NaCl were added to the growth media with the best growth observed at 3% NaCl, and the agardegrading enzyme activity of the cell culture supernatant was best when grown at 3% NaCl-containing growth media under the conditions we examined. The crude enzyme prepared from 48-h culture broth of strain SH-1 exhibited an optimum pH and temperature for agar-degrading activity at 7.0 and $40^{\circ}C$, respectively. Zymogram analysis of the crude supernatant and cell extract showed that strain SH-1 produced at least 3 agar-degrading enzymes with molecular weights of 15, 35, and 52 KD. Thinlayer chromatography (TLC) analysis also suggested that HS-1 produces ${\beta}$-agarase to degrade agarose to neoagarooligosaccharides.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.2
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• pp.198-203
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• 1999

Gonadal development and reproductive cycle off Gomphina melanaegis collected in the coastal waters of Chumunjin, Korea were investigated monthly from April 1996 to April 1997. G. melanaegis was dioecious, The gonads were located between the digestive diverticula and muscle tissues of the foot, The ovary was composed of a number of ovarian sacs, and the testis was composed of several testicular tubules. The flesh weight rate was reached the maximum in August ($23.0\%$), and then decreased to $19.8\%$ in September. In March, the value was reached the minimum ($17.8\%$) and then increased, The size of mature oocyte was ranged $50\~60\mu$m in diameter and had a germinal vesicle with a nucleolus. Mature oocyte contained a large number of yolk granules and lipid granules in its cytoplasm. The spermatozoon was consisted of a conical nucleus with acrosome, a middle piece containing four mitochondria and proximal and distal centrioles, and a flagellum, Sex ratio (male/female) and minimum size for sexual maturation of G. melanaegis were 0.79 and about 25 mm in shell length, respectively. The reproductive cycle could be classified into five succesive stages: multiplicative (December to March), growing (April and May), mature(June), sprawning (July and August), and degenerative and resting (September to November) stages.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.183-191
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• 2007

The external ultrastructural morphology and distribution of antennal sensilla and hair-pencils of Palpita indica (Saunder) were examined by scanning electron microscopy. The antennal flagellum of male and female has six types of sensilla: long trichodea, short trichodesa, chaetica, coeloconicum around spines, camaniformia and styloconica. There are sexual differences in antennae of P. indica. The female antenna has a coeloconicum sensillum without spines nearby the long trichodea sensilla on ninth flagellomere. Otherwise, auricillica sensilla are distribute on the basal segment of male antenna. These structures are not showed in the female antenna. There are a lot of pores on the hair tufts of the male hair-pencils.