• ALGAE
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• 제31권2호
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• pp.155-165
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• 2016

Green microalgae from the class Chlorophyceae represent a major biodiversity component of eukaryotic algae in continental water. Identification and classification of this group through morphology is a hard task, since it may present cryptic species and phenotypic plasticity. Despite the increasing use of molecular methods for identification of microorganisms, no single standard barcode marker is yet established for this important group of green microalgae. Some available studies present results with a limited number of chlorophycean genera or using markers that require many different primers for different groups within the class. Thus, we aimed to find a single marker easily amplified and with wide coverage within Chlorophyceae using only one pair of primers. Here, we tested the universality of primers for different genes (tufA, ITS, rbcL, and UCP4) in 22 strains, comprising 18 different species from different orders of Chlorophyceae. The ITS primers sequenced only 3 strains and the UCP primer failed to amplify any strain. We tested two pairs of primers for rbcL and the best pair provided sequences for 10 strains whereas the second one provided sequences for only 7 strains. The pair of primers for the tufA gene presented good results for Chlorophyceae, successfully sequencing 21 strains and recovering the expected phylogeny relationships within the class. Thus, the tufA marker stands out as a good choice to be used as molecular marker for the class.

• 농업과학연구
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• 제27권1호
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• pp.13-19
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• 2000

SEM을 이용하여 아메리카잎굴파리 (Liriomyza trifoljj) 의 암 수컷 성충의 외부형태적 특정을 살펴보았다. 더듬이에 있어 감각모의 3가지 형태는 더듬이가는마디(funicle)에서 관찰되었으며, 모상감각기(trichoid sensillum)는 말단 부위가 뽀족한 특정적인 형태를 하고 있고 감각기들 중에서 가장 많이 분포하고 있다. 원추상 감각기(basiconic sensillum)는 길이가 $13{\mu}m$, 지름이 $1.4{\mu}m$에서 $1.2{\mu}m$인 원형곡선형이다. 홈형 감각기 (grooved sensillum)는 간상 (peg) 끝에서 나온 손 모양을 하고 있으며, 이 모든 감각기들은 후각과 연관되어져 있는 것으로 추정된다. 구기는 흡즙형으로 작고 펼쳐진 윗입술(labrum) 과 합쳐져서 하나의 연결된 주둥이(rostrum)을 형성하고 있다. 가느다란 한 쌍의 작은턱수염 (maxillary palp)은 긴 관 모양으로 각각의 세로로 이어져 있다. 발마디는 5마디로 이루어져 있으며 그 한가운데에는 패드모양의 흡착반(pulvillus)과 가시모양의 발톱사이돌기(empodium)가 있다. 아메리카잎굴파리는 흡착반과 발톱사이돌기에서 미끄러운 표변에 부착할 수 있는 물질을 분비한다. 수컷의 생식기는 매우 복잡하며 삽입구(aedeagus)는 생식기관으로서 가장 일반적인 모양이다. 반면에 암컷의 생식기는 상대적으로 간단한데 이 구조는 외부로 돌출된 관모양이었다. 또한 이러한 결과를 이미 발표된 다른 여러 종의 파리와 비교하였다.

• Animal Systematics, Evolution and Diversity
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• 제31권4호
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• pp.209-246
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• 2015

Morphological features of larvae and pupae of twelve species of Simulium (Simulium) from Korea are investigated and redescribed. Detailed descriptions of immature stages of each species are provided with photographs. For the Korean members of subgenus Simulium, combinations of the following characteristics can be used to separate them from other Korean subgenera: larval abdomen without a pair of conical-shaped ventral tubercles; postgenal cleft variously shaped, viz., miter shaped, spearhead, bullet shaped or triangular; rectal papillae 3 simple lobe or compound lobes; pupal gill of 6-16 filaments; cocoon shoe, boot or slipper shaped; and head trichomes 3 pairs (1 facial+2 frontal). Habitat information and other ecological aspects of each species are provided. Updated keys to larvae and pupae of the Korean species of the subgenus Simulium are also provided to facilitate species identification. Taxonomic treatment based on external morphologies of larvae and pupae of Korean species of the subgenus Simulium are focused and included in this study. To understand their interspecific relationships, phylogenetic analyses using multiple data from molecule, morphology, and ecology are warranted in future research. Also continued exploration for new character systems is needed to establish more stable boundaries for subgenus and species delimitations.

• 한국패류학회지
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• 제22권2호
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• pp.115-124
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• 2006

Gonad index, spermatogenesis and the reproductive cycle of Meretrix petechialis were investigated by cytological, histological observations. Monthly changes in the gonad index coincides the gonadal development. The morphology of the spermatozoon had a primitive type and is similar to that of other bivalves having a short mid-piece with five to six mitochondria surrounding the centrioles. The morphology of the sperm nucleus type and the acrosome shape of this species were cylindrical type and cap-like shape, respectively. The spermatozoon was approximately 40-45 ${\mu}m$ in length including the sperm nucleus length (about 1.50 ${\mu}m$), acrosome length (0.60 ${\mu}m$) and tail flagellum. The axoneme of the tail flagellum consisted of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail showed 9 + 2 microtubular arrangement. The spawning period was from June to September and the main spawning occurred from July to August when seawater temperatures were higher than $20^{\circ}C$. The reproductive cycle of this species could be categorized into five successive stages: early active stage (February to March), late active stage (February to May), ripe stage (April to July), partially spawned stage (June to September), and spent/inactive stage (September to February).

• 한국패류학회지
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• 제27권4호
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• pp.377-386
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• 2011

The ultrastructures of germ cells during spermatogenesis and sperm morphology in male Mya arenaria oonogai, which was collected on the coastal waters of Samcheonpo, south coast of Korea, were investigated by transmission electron microscopic observations. In the early stage of the spermatid during spermiogenesis, a few granules and a proacrosomal granule, which is formed by the Golgi complex, appear on the spermatid nucleus, and then it becomes a proacrosomal vesicle. Consequently, it becomes an acrosome by way of the process of acrosome formation. The morphologies of the sperm nucleus type and the acrosome of this species have a curved cylindrical type and cone shape, respectively. The spermatozoon is approximately $48-50{\mu}m$ in length including a curved cylinderical sperm nucleus (about $2.65{\mu}m$ long), an acrosome (about $0.64{\mu}m$ in length) and tail flagellum ($40-45{\mu}m$ long). As some ultrastructural characteristics of the acrosomal vesicle, the peripheral parts of two basal rings show electron opaque part (region), while the apex part of the acrosome shows electron lucent part (region). These charateristics of the sperm belong to the family Myidae or some species of Veneridae in the subclass Heterodonta, unlike a characteristic of the subclass Pteriomorphia showing all part of the acrosome being composed of electron opaque part (region). Therefore, it is easy to distinguish the families or the subclasses by the acrosome structures. Exceptionally, In particular, a cylinder-like nucleus of the sperm is curved (the angle of the nucleus is about $20^{\circ}$), as seen in some species of Veneridae (range from $0^{\circ}-80^{\circ}$). The number of mitochondria in the midpiece of the sperm of this species are four, as one of common characteristics appeared in most species except for a few species in Veneridae in the subclass Heterodonta. Cross-sectioned axoneme of the sperm tail flagellum shows a 9+2 structure: the axoneme of the sperm tail flagellum consists of nine pairs of peripheral microtubules at the periphery and a pair of central doublets at the center.

• Bulletin of the Korean Chemical Society
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• 제30권9호
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• pp.2071-2076
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• 2009

The single-walled carbon nanotubes (SWCNTs) produced by chemical vapor deposition (CVD) were directly fluorinated with fluorine ($F_2$) gas in a temperature range 20 ~ 400 ${^{\circ}C}$. The surface properties and morphology of the SWCNTs were investigated in terms of fluorination temperature. As a result, Raman spectra showed a pair of bands at 1340 and 1590 $cm^{-1}$ peculiar to disordered $sp^2$-carbons. These results indicated that C-F bonds were formed on the rear surfaces of the nanotubes by fluorination, while the external surfaces as well as the layers between the internal and external surfaces retained their $sp^2$-hybridization. XPS analysis exhibited that fluorine atoms were bonded to carbon atoms on internal surfaces (rear surfaces) of the nanotubes and the amount of fluorine attached on the nanotubes was increased with increasing the fluorination temperature. Consequently, the direct fluorination of carbon nanotubes led to functionalization and modification of pristine nanotubes with respect to surface and morphological properties.

• 한국응용과학기술학회지
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• 제26권2호
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• pp.199-204
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• 2009

Silicone dioxide absorbed polyoxyethylene alkylether sulfate (EU-S133D) surfactant was prepared. Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using Acrylate as a shell monomer and potassium persulfate (KPS) as an initiator. We found that when Acrylate core prepared by adding 2.0 wt% EU-S133D, silicone dioxide/Acrylate core-shell polymerization was carried out on the surface of silicone dioxide particle without forming the new silicone dioxide particle during acrylate shell polymerization in the inorganic/organic core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer and morphology of latex by scanning electron microscope(SEM).

• 한국응용과학기술학회지
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• 제27권1호
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• pp.56-60
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• 2010

Titanium dioxide particles are used as photocatalysts, sensors, adsorbents and catalyst. Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using Acrylate as a shell monomer and potassium persulfate (KPS) as an initiator. We found that when Acrylate core prepared by adding 0.5~2.0 wt% EU-S133D, Titanium dioxide / Acrylate core-shell polymerization was carried out on the surface of Titanium dioxide particle without forming the new Titanium dioxide particle during acrylate shell polymerized in the inorganic/organic core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer(TGA) and morphology of latex by scanning electron microscope(SEM).

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.295-295
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• 2006

In present study, poly(acrylic acid) (PAA) and hydrophobically modified poly(ethylene oxide) (HM-PEO) multilayers based on the hydrogen bonding between the component polymer pair have been prepared by the LbL deposition method. Dip assembled HM-PEO/PAA multilayers yield unique film morphologies in comparison with PEO/PAA multilayers due to the micellar formation of HM-PEO owing to the hydrophobic attraction between alkyl chains end-capped with the PEO chains. Individual HM-PEO micelles were connected through the bridging PEO chains to form temporary networks on multilayer surface and induced peculiar surface morphology on HM-PEO/PAA multilayers above the critical number of bilayers.

• 한국잠사곤충학회지
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• 제41권2호
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• pp.87-93
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• 1999

Under Light and Scanning electron microscope, the pupal morphology of mulberry silkworm Bombyx mori Linn. revealed the prothorax and metathorax, well developed mesothorax, less defined last pair of sporacle, well exposed prothoracic femora and wing pads approaching the anterior margin of Ab III. The important sex separating characters viz, wegiht, antennal elevations, intersegmental lines and genings have discussed. Further, two separate openings bursa copulatrix and ovipositional opening were observed, performing different functions in abult moth.