Hyuk Je Lee

Sangji University · Molecular Ecology and Evolution Lab, Department of Biological Science

Seagrasses provide numerous ecosystem services for coastal and estuarine environments, such as nursery functions, erosion protection, pollution filtration, and carbon sequestration. Zostera marina (common name “eelgrass”) is one of the seagrass bed-forming species distributed widely in the northern hemisphere, including the Korean Peninsula. Recent...

The Manchurian trout, Brachymystax lenok tsinlingensis (family: Salmonidae), is a cold freshwater fish endemic to Northeast Asia. South Korean populations of this species, which comprise its southern range limit, have recently decreased markedly in size and are now becoming critically endangered. We assessed the current population status of this sp...

The coastal ecosystems are considered as one of the most dynamic and vulnerable environments under various anthropogenic developments and the effects of climate change. Variations in the composition and diversity of microbial communities may be a good indicator for determining whether the marine ecosystems are affected by complex forcing stressors....

Alloparental care – care for unrelated young – is rare in animals, and its ecological or evolutionary advantages or, alternative maladaptive nature, remain unclear. We investigate alloparental care in the socially monogamous cichlid fish Perissodus microlepis from Lake Tanganyika that exhibits bi-parental care. In a genetic parentage analysis, we d...

The genetic dissection of naturally occurring phenotypes sheds light on many fundamental and longstanding questions in speciation and adaptation and is a central research topic in evolutionary biology. Until recently, forward-genetic approaches were virtually impossible to apply to non-model organisms, but the development of next-generation sequenc...

Bitterling fishes evolve an idiosyncratic symbiosis with freshwater mussels, in which they are obligated to spawn in the gills of mussels for reproduction. In recent years, freshwater mussel populations have been drastically diminishing, due to accelerating anthropogenic impacts, which can be large threats to the risk of bitterling's extinction cas...

The main objectives of this study were to analyze the spatiotemporal variations of water quality, fish ecological guilds and longitudinal connectivity in the weirs of Musim Stream. Fish were collected at 44 sites during spring and fall seasons for the analysis of trophic guilds, tolerance guilds, and the ecological stream health, based on FAI model...

Background: Longitudinal connectivity in river systems strongly affects biological components related to ecosystem functioning, thereby playing an important role in shaping local biodiversity and ecosystem health. Environmental DNA (eDNA)-based metabarcod-ing has an advantage of enabling to sensitively diagnose the presence/absence of species, beco...

River estuaries are dynamic and productive ecosystems with high regional biodiversity. Environmental DNA (eDNA) has become a useful approach to assessing biodiversity in aquatic ecosystems. This study was conducted to investigate fish community characteristics and species diversity in two river estuary ecosystems, the Taehwa River and Changwon Stre...

This study focused on the longitudinal connectivity analysis, based on fish communities in the aspect of spatial variations of 34 sites from upstream to downstream. The Fish Assessment Index (FAI), based on ecological guilds and species composition, was applied to compare the ecological health among the sampling sites. The total number of 35 fish s...

Bitterling fishes evolve an idiosyncratic symbiosis with freshwater mussels, in which they are obligated to spawn in the gills of mussels for reproduction. In recent years, freshwater mussel populations have been drastically diminishing, due to accelerating anthropogenic impacts, which can be large threats to the risk of bitterling’s extinction cas...

The main objectives of this study were to evaluate biological integrity analysis and longitudinal connectivity assessment in Tan Stream. The research included the analysis of chemical water quality, ecological health assessment based on fish, and a comparison of aquatic ecosystem health before and after restoration, following the removal of two wei...

The bitterling (Cyprinidae, Acheilongnathinae) is a temperate freshwater fish with a unique spawning symbiosis with host mussels. Female bitterlings use their extended ovipositors to lay eggs on the gills of mussels through the mussel's exhalant siphon. In the present study, in April of 2020, we investigated spawning frequencies and patterns of thr...

The spotted sleeper, Odontobutis interrupta, is a fish species endemic to Korea and shows potential as an aquaculture species. Nevertheless, the population size of this species has declined significantly in recent years. To characterize the population structure and genetic diversity of O. interrupta in Korea, we analyzed four microsatellite loci in...

Tilapia is an invasive species that has become widely distributed around the world. In Korea, introduced tilapia into its aquatic ecosystem for the first time with a species from Thailand in 1955, and later additionally introduced two more species from Japan and Taiwan, thus securing a total of three species of tilapia (O. niloticus, O. mossambicus...

Population or habitat connectivity is a key component in maintaining species and community-level regional biodiversity as well as intraspecific genetic diversity. Ongoing human activities cause habitat destruction and fragmentation, which exacerbate the connectivity due to restricted animal movements across local habitats, eventually resulting in t...

In recent years, macroalgal bloom occurs frequently in coastal oceans worldwide. It might be attributed to accelerating climate change. "Green tide" events caused by proliferation of green macroalgae (Ulva spp.) not only damage the local economy, but also harm coastal environments. These nuisance events have become common across several coastal reg...

Chum salmon (Oncorhynchus keta) is an ecologically and economically important species widely distributed across the North Pacific Ocean. However, the population size of this fishery resource has declined globally. Identifying genetic integrity, diversity and structure, and phylogenetic relationships of wild populations of O. keta over an entire spe...

Large-scale Sargassum blooms have been increasingly observed in coastal zones in recent years. Sargassum horneri (Turner) C.Agardh blooms (pelagic) have been observed in Jeju Island (Korea) and the southwest of the Korean Peninsula, causing serious problems for seaweed and abalone farms as well as for fisheries, tourism and recreational industries....

This study aimed to investigate the dynamics of the nutrient budget of a macroalgal community exposed to water discharged from aquaculture farms. This study was conducted in the coastal area exposed to water discharged from aquaculture farms located on Jeju Island, Korea, in May and October of 2017. Water-column-dissolved inorganic nutrient concent...

The Antarctic toothfish, Dissostichus mawsoni, serves as a valuable fishery resource around the Antarctic Continent since 1997, managed by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). Although delineating genetic or stock structure of populations is crucial for improving fishery management of this species, its...

Dispersal plays an important role in the ecological and evolutionary processes of natural populations. Mating behavior (or mating system) is a critical factor shaping dispersal patterns and extents in social mammals, sometimes driving the evolution of sex-biased dispersal. Using molecular markers with contrasting modes of inheritance (mitochondrial...

Mitochondrial genome sequences were first determined and analyzed for a Korean endemic freshwater mussel Nodularia breviconcha (synonym Nodularia douglasiae sinuolatus; Unionidae, Unionida, Bivalvia). The complete mitochondrial genome was 15,741 bp in length, including 13 protein-coding genes (PCGs), 22 tRNA genes, and 2 rRNA genes. The overall GC...

We conducted a phylogeographic analysis of Korean endemic Zacco koreanus populations inhabiting the East-flowing river (Gangneung Yeongokcheon; GY, Yangyang Namdaecheon; YN), the Han River (Seomgang; SG, Soksacheon; SS), and the Nakdong River (Gilancheon; GA) using the mitochondrial DNA cytochrome oxidase I (COI) gene (619 bp). Population genetic a...

Drifting and inundating brown seaweed Sargassum horneri biomass is called "golden tide", as it resembles golden massive algal blooms like green tides. This phenomenon occurs globally and its serious ecological impacts on coastal ecosystems have recently begun to be paid attention to. In the present study, by sequencing whole organelle genomes of Ko...

To determine the distribution of dissolved organic matter (DOM) in the East China Sea (ECS) during the summer, we measured the dissolved organic carbon (DOC) and nitrogen (DON), fluorescent dissolved organic matter (FDOM), and chlorophyll a (Chl. a) in the upper 100-m layer of this region during July and September 2015. The DOC (r2 = 0.72 and 0.78...

We investigated the growth and bioremediation potential of five local seaweed species (Codium fragile, Ulva pertusa, Ecklonia stolonifera, Saccharina japonica and Gracilariopsis chorda), using an integrated fish‐seaweed culture system as a biofilter for effluents from black rockfish (Sebastes schlegelii) tanks. The specific growth rate, biomass and...

The long-tailed goral (also called the Amur goral) Naemorhedus caudatus (subfamily Caprinae), a vulnerable and protected species designated by IUCN and CITES, has sharply been declining in the population size and is now becoming critically endangered in South Korea. This species has been conserved as a natural monument by the Korean Cultural Herita...

Since 2015, troublesome masses of floating Sargassum horneri have been introduced via ocean currents and winds to the southwestern coastline of Korea, including Jeju Island. These massive mats have caused considerable damage to the aquaculture industry, tourism, and the marine ecosystem. Most previous studies of S. horneri have focused on cultivati...

Marine ecosystems in temperate regions have been significantly affected by rising seawater temperatures due to climate change. Alveopora japonica, a small zooxanthellate scleractinian coral, occurs in the northwestern Pacific including Taiwan, Japan, and Jeju Island in Korea. The northern populations around Jeju Island have recently undergone rapid...

Species diversity in the genus Ulva remains understudied worldwide. Using molecular analyses we investigated the species composition, diversity, distribution, and relative frequencies of the genus Ulva along the entire coast of Jeju Island, off the southern tip of Korea. Species identification was performed for 215 samples collected from 23 sites,...

In recent years, drifting and inundating brown seaweed (Sargassum horneri) biomass, called ‘golden tides’, has frequently drifted and accumulated along the southern coastlines of Korea, causing devastating impacts on the local economy and coastal ecosystems. In this study, based on combined analyses of mitochondrial DNA cox3 gene and seven microsat...

This study was conducted to investigate the spawning preference of the Acheilognathinae fishes in relation to the shell size of host mussels after identifying the species of eggs and fries in the host mussel using our recently developed RFLP (Restriction Fragment Length Polymorphism) molecular marker at four sites [Hongcheon Naechoncheon (HN) and D...

Background: Life history characteristics are considered important factors influencing the evolutionary processes of natural populations, including the patterns of population genetic structure of a species. The sister species Cottus hangiongensis and C. koreanus are small bottom-dwelling freshwater sculpin fishes from South Korea that display marke...

This study aimed to examine the levels of genetic diversity, genetic structure and phylogeographic relationships among natural populations of the greater horseshoe bat, Rhinolophus ferrumequinum inhabiting nine national parks including the Baekdudaegan Mountain Range, based on mitochondrial DNA control region. Levels of genetic diversity, as estima...

This study aimed to develop a species identification method for the egg and fry of the three Korean bitterling fishes (Pisces: Acheilognathinae), including Acheilognathus signifer, Acheilognathus yamatsutae and Rhodeus uyekii based on the PCR-based Restriction Fragment Length Polymorphism (RFLP) markers. We conducted a field survey on the Deokchich...

We conducted testing to determine whether stipe length is a useful indicator of reproductive maturity in the kelp Ecklonia cava, a species that plays a pivotal role in ecosystem functioning and services in subtidal areas. Approximately 100 sporophytes with stipes of various lengths were collected during the fertile period (July–November, 2013). We...

Lateralized behavior ('handedness') is unusual, but consistently found across diverse animal lineages, including humans. It is thought to reflect brain anatomical and/or functional asymmetries, but its neuro-molecular mechanisms remain largely unknown. Lake Tanganyika scale-eating cichlid fish, Perissodus microlepis show pronounced asymmetry in the...

Because kelp biomass contributes to the abundance and production of myriad animals and plants in coastal marine ecosystems, its measurement is critical to evaluating the impact of macroalgae on marine and aquatic habitats. We investigated the relationships among morphological characteristics to develop a non-destructive method for calculating Ecklo...

Statistical tests for a recent bottleneck in each of the 16 populations (including temporally replicated and depth samples) of Zostera marina from South Korea. (DOCX)

Analyses of temporal population structure using a Bayesian population assignment test with STRUCTURE, based on eight microsatellite loci. (DOCX)

Cordyceps militaris (a caterpillar fungus), which belongs to the class Ascomycetes, has extensively been used for medicinal purposes in East Asia. Here, we isolated and characterized 12 microsatellite loci from the medicinal mushroom, C.militaris. Twenty-nine individual samples were taken from a single locality in southwestern Korea and used to cha...

The scale-eating cichlid fish, Perissodus microlepis, from Lake Tanganyika are a well-known example of an asymmetry dimorphism because the mouth/head is either left-bending or right-bending. However, how strongly its pronounced morphological laterality is affected by genetic and environmental factors remains unclear. Using quantitative assessments...

The present-day genetic structure of a species reflects both historical demography and patterns of contemporary gene flow among populations. To precisely understand how these factors shape current population structure of the northwestern (NW) Pacific marine gastropod, Thais clavigera, we determined the partial nucleotide sequences of the mitochondr...

Genotyping at eight SNPs in the LELCC (Letinula edodes laccase) gene from each shiitake line

Multiple sequence alignment of the LELCC (Letinula edodes laccase) gene sequences (2,249 bp) of 89 shiitake lines, illustrating locations of the single nucleotide polymorphism polymorphisms identified. R = A or G, Y = C or T, K = G or T, M= A or C, S = G or C, and W = A or T.

We identified single nucleotide polymorphism (SNP) markers in the laccase gene to establish a line-diagnostic system for shiitake mushrooms. A total of 89 fungal isolates representing four lines, including Korean registered, Korean wild type, Chinese, and Japanese lines, were analyzed. The results suggest that SNP markers in the laccase gene can be...

Bumblebee Bombus ignitus, which is indigenous to Korea, Japan, and China, has been recognized as a valuable pollinator for both crops and wild plants. Bombus ignitus has now become commercially important as a pollinator because of its use in the agricultural industry, particularly for greenhouse pollination. For long-term management and effective c...

The effects of intensity and timing of disturbances on recovery of marine benthic organisms were investigated on a rocky intertidal shore in Gwangyang Bay, Korea. We hypothesized that the recovery pattern of the benthic community structure would be affected by disturbance intensity and season. Twenty-eight permanent plots were set up, with disturba...

Patterns in the recruitment, distribution, and persistence of three Ulva species, which can form green tides, were investigated in relation to surface roughness using artificial substrates on intertidal rocky shores of the southern coast of Korea. The vertical distributions of Ulva pertusa, Ulva linza, and Ulva compressa were well separated: U. com...

We tested the hypothesis that the community structure and biochemical composition of macroalgae reflect the degree of nutrient concentrations in the water column. Benthic community structure and tissue nitrogen (N) content of macroalgae on intertidal rocky shores at three sites were investigated in relation to sewage effluents on Mireuk Island, Ton...

Individuals of the scale-eating cichlid fish, Perissodus microlepis, from Lake Tanganyika tend to have remarkably asymmetric heads that are either left-bending or right-bending. The 'left' morph opens its mouth markedly towards the left and preferentially feeds on the scales from the right-hand side of its victim fish, and the 'right' morph bites s...

Scale-eating cichlid fish, Perissodus microlepis, from Lake Tanganyika display handed (lateralized) foraging behavior, where an asymmetric 'left' mouth morph preferentially feeds on the scales of the right side of its victim fish and a 'right' morph bites the scales of the left side. This species has therefore become a textbook example of the aston...

Lateralized foraging behavior in adult Perissodus microlepis: foraging preferences and foraging scores. (DOC)

The introduction of invasive Nile tilapia (Oreochromis niloticus), and the rapacious predator Nile perch (Lates niloticus), into Lake Victoria resulted in a decline in population sizes, genetic diversity and even extirpation of native species which were previously the mainstay of local fisheries. However, remnant populations of native fish species,...

Natural populations of widely-distributed animals often exhibit clinal variation in phenotypic traits or in allele frequencies of a particular gene over their geographical range. A planktotrophic intertidal snail, Littorina keenae is broadly distributed along the north-eastern Pacific coast through a large latitudinal range (24°50´N-43°18´N). We te...

Population genetic analyses were conducted to investigate whether random mating occurs between left and right-mouth morphs of the dimorphic scale-eating cichlid fish Perissodus microlepis from two geographical sites in southern Lake Tanganyika. The mitochondrial and nuclear DNA markers (13 microsatellite loci) revealed no genetic differentiation be...

We investigated the effect of development mode on the spatial and temporal population genetic structure of four littorinid gastropod species. Snails were collected from the same three sites on the west coast of Vancouver Island, Canada in 1997 and again in 2007. DNA sequences were obtained for one mitochondrial gene, cytochrome b (Cyt b), and for u...

The present population structure of a species reflects the influence of population history as well as contemporary processes. To examine the relative importance of these factors in shaping the current population structure of Littorina keenae, we sequenced 762 base pairs of the mitochondrial ND6 and cytochrome b genes in 584 snails from 13 sites alo...

Interspecific interactions among three dominant macroalgae, Pterocladia capillacea (Rhodophyta), Hizikia fusiformis (Heterokontophyta) and Chondracanthus intermedius (Rhodophyta), were experimentally investigated on the rocky mid-intertidal zone of Sungsan, Jeju Island, Korea from March 1998 to June 1999. Each of the potentially competing species w...