In vivo growth-inhibition of S 180 tumor by mixture of 5-Fu and low molecular lambda-carrageenan from Chondrus ocellatus

POLYSACCHARIDES; ANTICOAGULANT; SURVIVAL

Effects of temperature and irradiance on early development of Chondrus ocellatus Holm (Gigartinaceae, Rhodophyta)

Chondrus is a type of commercially produced red seaweed that widely used for food and carrageen extraction. Although the natural life history of the alga had been well understood, the factors influencing development of the tetraspore and carpospore remain poorly understood. In the perspective of seedling resources, the regulation of early development is crucial for the seedling nursing; therefore, it is necessary to understand the physiological influences during its early development. In this study, we studied the effects of temperature and irradiance on the early development of Chondrus ocellatus Holm under laboratory conditions. The released tetraspores and carpospores were cultivated at different temperatures (10-28 degrees C) and irradiances ( 10, 60 mu mol photons m(-2)s(-1)) with a photoperiod of 12L:12D. The results indicate that both tetraspores and carpospores are tolerant to temperatures of 10-25 degrees C, and have the highest relative growth rate at 20 degrees C. Irradiance variances influenced the growth of the discoid crusts, and the influence was more significant with increasing temperature; 60 mu mol photons m(-2)s(-1) was more suitable than 10 mu mol photons m(-2)s(-1). The optimum temperature and irradiance for the development of seedlings was 20 degrees C and 60 mu mol photons m(-2)s(-1), respectively.

In vivo antitumor and immunomodulation activities of different molecular weight Lambda-Carrageenans from Chondrus ocellatus

lambda-Carrageenan is a sulfated galactan isolated from some red algae and have been reported to have many kinds of biological activities. lambda-Carrageenan from Chondrus ocellatus, an important economic alga in China and many other parts of the world, was degraded by microwave, and obtained five products that have different molecular weight: 650, 240, 140, 15, 9.3 kDa. Analytical results confirmed that microwave degradation might not change the chemical components and structure of polysaccharides under certain condition. In this study, tumor-inhibiting activities, weight of immune organ, nature killer cells activity, lymphocyte proliferation ratio and pathological slice of spleen and tumor cells from the control group and lambda-carrageenan-treated mice of transplanted S 180 and H22 tumor were investigated. The results indicated that the five lambda-carrageenan samples all showed antitumor and immunomodulation activities in different degree. Molecular weight of polysaccharides had notable effect on the activities. In addition, their antitumor and immunomodulation have some relevance and the five lambda-carrageenans probably inhibited tumor by means of activating the immunocompetence of the body. Among all the experiment results, samples with the highest activities are PC4 and PC5 whose molecular weight are 15 and 9.3 kDa. (C) 2003 Elsevier Ltd. All rights reserved.

Inter-simple sequence repeat (ISSR) analysis of genetic variation of Chondrus crispus populations from North Atlantic

ISSR analysis was used to investigate genetic variations of 184 haploid and diploid samples from nine North Atlantic Chondrus crispus Stackhouse populations and one outgroup Yellow Sea Chondrus ocellatus Holmes population. Twenty-two of 50 primers were selected and 163 loci were scored for genetic diversity analysis. Genetic diversity varied among populations, percentage of polymorphic bands (PPB) ranged from 27.0 to 55.8%, H(Nei's genetic diversity) ranged from 0.11 to 0.20 and I(Shannon's information index) ranged from 0.16 to 0.30. Estimators PPB, H and I had similar values in intra-population genetic diversity, regardless of calculation methods. Analysis of molecular variance (AMOVA) apportioned inter-population and intra-population variations for C crispus, showing more genetic variance (56.5%) occurred in intra-population, and 43.5% variation among nine populations. The Mantel test suggested that genetic differentiation between nine C. crispus populations was closely related with geographic distances (R = 0.78, P = 0.002). Results suggest that, on larger distance scale (ca. > 1000 km), ISSR analysis is useful for determining genetic differentiations of C crispus populations including morphologically inseparable haploid and diploid individuals. (c) 2007 Elsevier B.V. All rights reserved.

角叉菜四分孢子和果孢子早期发育的研究

角叉菜（Chondrus）是一种重要的经济红藻，广泛应用于食品行业及卡拉胶的提取工业。从种苗繁育的角度看，对角叉菜早期发育的研究意义重大。自然环境下角叉菜的生活史循环已得到阐释，但对其四分孢子及果孢子在室内条件下的早期发育过程还远远了解不够，因此有必要对其早期发育的具体特征和影响因素进行详细的分析研究。 本研究以青岛海域常见的角叉菜（Chondrus ocellatus Holm）作为实验材料，分析了实验室培养条件下温度及光强两个环境因子对其四分孢子和果孢子早期生长发育的影响，同时对整个发育过程进行了观察与记录。研究结果表明角叉菜两种孢子的早期生长发育过程基本一致，从孢子附着后萌发到长出幼苗，整个过程经历三个发育阶段：分裂期、盘状体期和直立幼苗形成期。另外，在早期发育过程中观察到多个盘状体融合的现象，这种融合使得孢子幼苗对基质的附着更加稳固，有利于其生存。通过设定6个温度梯度（10℃、15℃、20℃、22℃、25℃、28℃）及2个不同光照强度（10、60 μmol photos m-2s-1）条件，确立了角叉菜果孢子及四分孢子最适培养温度为20℃，而最适光照强度为60 μmol photos m-2s-1。角叉菜四分孢子和果孢子的早期生长发育均显示出较宽的温度耐受范围（10-25℃），但在28℃的高温条件下，两种孢子均会逐渐褪色死亡。分别采用单因素方差分析和独立样本t检验两种统计学方法分析温度和光强的影响，发现温度、光强的变化对角叉菜盘状体生长均有显著性影响。高光照可促进两种孢子的生长与发育，而低温（10℃）则会抑制孢子的的生长与发育。

红藻无性繁殖系的诱导及其发育机制的初步研

以红藻中的角叉菜（Chondrus ocellatus）、龙须菜（Gracilaria lemaneiformis）、真江蓠(Gracilaria asiatica)和海膜（Halymenia sinensis）为材料，观察了红藻幼苗的早期发育，通过组织培养构建无性繁殖系，并初步探讨了红藻无性繁殖系的发育及分化机理，为海藻无性繁殖系的获得提供理论基础和依据。 在室内进行了角叉菜的四分孢子和果孢子的细胞培养，并观察其早期发育过程。结果表明，四分孢子和果孢子的早期发育是相似的，可主要分为三个阶段：早期分裂阶段、盘状体阶段和直立体形成阶段。 切段组织培养表明，红藻无性繁殖系的获得主要通过两种途径：一种为切段组织经过培养可直接形成再生植株；另一种为切段组织经培养脱分化，诱导出愈伤组织或类愈伤组织，愈伤组织或类愈伤组织再分化，形成盘状体，盘状体继续发育即可形成再生植株。 通过切段组织培养，获得了龙须菜和真江蓠再生植株。在PES培养液中，添加6－BA（0.25 mg/L）对龙须菜切段组织再生新枝的诱导有促进作用，诱导率可高达84.4％，高浓度的IAA或6－BA（4 mg/L）对切段组织有损伤作用。实验证明伤口大小对切段组织再生新枝有影响，且伤口太大对再生新枝的形成不利。龙须菜的切段组织培养过程中表现出极性。 通过组织培养，诱导出海膜类愈伤组织—丝状体。添加植物生长调节类物质（IAA 和 6-BA）对海膜丝状体的诱导无促进作用。海膜切片在消毒海水中培养即可获得丝状体。海膜丝状体的外植体来源主要有两个：一是健康的藻体； 另一是盘状体，其丝状体的诱导率分别为80％ 和90％。筛选出了丝状体适宜的生长条件：13－23℃，10－15 μE•m−2• s−1，12h：12h（Light: Dark），其中18℃为最佳生长温度。高的光照强度（50 μE•m−2•s−1）对丝状体产生损伤作用。 红藻无性繁殖系的发育途径，根据其获得途径也有两种情况。经过切段组织培养直接获得的无性繁殖系，是切段切口处已分化的细胞表现其全能性，恢复分裂能力，再生新枝，切段表现出极性。极性的上端产生新枝，下端形成固着器，成为一个完整的植株。经过愈伤组织和类愈伤组织获得的无性繁殖系，是切口处已分化的细胞表现其全能性，经脱分化形成愈伤组织和类愈伤组织，附着在基质上后，再分化形成盘状体，按照孢子的早期发育途径，形成直立体幼苗。 通过SDS-聚丙烯酰胺凝胶电泳分析，对龙须菜正常藻体及无性繁殖系发育过程中蛋白的表达进行检测，检测出表达差异的蛋白质，推测这两个蛋白可能与龙须菜切段组织再生有关，其中30 KD的蛋白仅在再生新枝中表达，150 KD和125 KD的蛋白仅在正常生长的龙须菜和龙须菜切段的极性下端中表达。 根据高等植物中与萌芽、分生组织以及愈伤组织发育相关的基因序列保守区设计了五对特异引物，通过PCR和RT-PCR扩增检测及DNA测序分析，对红藻无性繁殖系早期发育相关的基因序列，进行了初步分析。

Phylogeography of the Northern Atlantic species Chondrus crispus (Gigartinales, Rhodophyta) inferred from nuclear rDNA internal transcribed spacer sequences

Eighteen isolates of the red algae Chondrus crispus were collected from Northern Atlantic sites, together with C. ocellatus, C. yendoi and C. pinnulatus from the North Pacific. The nuclear rDNA internal transcribed spacer (ITS) was sequenced and compared, spanning both the ITS regions and the 5.8S rRNA gene. Percentage of nucleotide variation for C. crispus ranged from 0.3% to 4.0%. Phylogenetic analyses were performed using maximum parsimony (MP), neighbor-joining (NJ) and minimum evolution methods. They showed that two main clades existed within the C. crispus samples examined and that suggested C. crispus had a single Atlantic origin. The clustering however did not follow the geographic origin. We hypothesized that the current distribution of C. crispus populations might be a result of three main factors: temperature boundaries, paleoclimate and paleoceanography. ITS data exhibited abundant molecular information not only for phylogeographical investigation but also for systematics studies.

An evaluation of Northern Florida Bay as a nursery area for red drum, Sciaenops ocellatus, and other juvenile and small resident fishes.

Red drum is one ofthe most popular species sought by anglers in Florida Bay, yet juveniles are rarely encountered. We evaluated Florida Bay as a nursery area for red drum by sampling for recently-settled late larvae in basin areas within the bay with an epi-benthic sled at six stations in November 2000, and at seven stations during December 2000 through February 2001. In November 2000 we surveyed potential sampling sites in quiet backwaters adjacent to mangroves for juvenile red drum. A total of 202 sites were sampled mainly in northern Florida Bay and adjacent waters with a cast net. We collected only one recently-settled red drum larvae and no juveniles. Obviously the sites that we sampled in Florida Bay and adjacent waters are not nursery habitat for this valuable species. Sled collections were dominated by bay anchovy, Anchoa mitchilli, but densities were biased by one collection. Five small resident species were among the dominant species: rainwater killifish, Lucania parva; dusky pipefish, Syngnathus floridae; dwarf seahorse, Hippocampus zosterae; and clown goby, Microgobius gulosus. Three species that spawn outside Florida Bay in the GulfofMexico were common: pinfish, Lagodon rhomboides; pigfish, Orthopristis chrysoptera; and silver perch, Bairdiella chrysoura. Twenty-seven species were collected with the cast net. Hardhead silversides (Atherinomorus stipes), bay anchovy, tidewater mojarra (Eucinostomus harengulus), silver jenny (Eucinostomus gula), and goldspotted killifish (Floridichthys carpio) were the most common in cast net collections. Although only one red drum was collected, we were able to: (1) identify mesohaline waters from our cast net sites to test our preliminary assessment that mesohaline habitat might be limited in Florida Bay, (2) document the distribution and abundance of fishes collected by cast net that should enhance our understanding of ichthyofauna in the Northern Subdivision ofFlorida Bay and adjacent waters, and (3) from epibenthic sled collections, describe the habitats, abundance and distribution of recently settled larvae/small juveniles/small resident fishes during late fall and winter. This information should be useful to managers and future research. (PDF contains 34 pages)

Variation in movement patterns of red drum (Sciaenops ocellatus) inferred from conventional tagging and ultrasonic telemetry

We used 25 years of conventional tagging data (n= 6173 recoveries) and 3 years of ultrasonic telemetry data (n=105 transmitters deployed) to examine movement rates and directional preferences of four age classes of red drum (Sciaenops ocellatus) in estuarine and coastal waters of North Carolina. Movement rates of conventionally tagged red drum were dependent on the age, region, and season of tagging. Age-1 and age-2 red drum tagged along the coast generally moved along the coast, whereas fish tagged in oligohaline waters far from the coast were primarily recovered in coastal regions in fall months. Adult (age-4+) red drum moved from overwintering grounds on the continental shelf through inlets into Pamlico Sound in spring and summer months and departed in fall. Few tagged red drum were recovered in adjacent states (0.6% of all recoveries); however, some adult red drum migrated seasonally from overwintering grounds in coastal North Carolina northward to Virginia in spring, returning in fall. Age-2 transmitter-tracked red drum displayed seasonal emigration from a small tributary, but upstream and downstream movements within the tributary were correlated with fluctuating salinity regimes and not season. Large-scale conventional tagging and ultrasonic telemetry programs can provide valuable insights into the complex movement patterns of estuarine fish.

Microsatellite primers for red drum (Sciaenops ocellatus)

In this note, we document polymerase-chain-reaction (PCR) primer pairs for 101 nuclear-encoded microsatellites designed and developed from a genomic library for red drum (Sciaenops ocellatus). Details of the genomic library construction, the sequencing of positive clones, primer design, and PCR protocols may be found in Karlsson et al. (2008). The 101 microsatellites (GENBA NK Accession Numbers EU015882-EU015982) were amplified successfully and used to genotype 24 red drum obtained from Galveston Bay, Texas (Table 1). A total of 69 of the microsatellites had an uninterrupted (perfect) dinucleotide motif, and 30 had an imperfect dinucleotide motif; one microsatellite had an imperfect tetranucleotide motif, and one had an imperfect and compound motif (Table 1 ). Sizes of the cloned alleles ranged from 84 to 252 base pairs. A ‘blast’ search of the GENBANK database indicated that all of the primers and the cloned alleles were unique (i.e., not duplicated).

Age composition and distribution of red drum (Sciaenops ocellatus) in offshore waters of the north central Gulf of Mexico: an evaluation of a stock under a federal harvest moratorium

Because of a lack of fishery-dependent data, assessment of the recovery of fish stocks that undergo the most aggressive form of management, namely harvest moratoriums, remains a challenge. Large schools of red drum (Sciaenops ocellatus) were common along the northern Gulf of Mexico until the late 1980s when increased fishing effort quickly depleted the stock. After 24 years of harvest moratorium on red drum in federal waters, the stock is in need of reassessment; however, fisherydependent data are not available in federal waters and fishery-independent data are limited. We document the distribution, age composition, growth, and condition of red drum in coastal waters of the north central Gulf of Mexico, using data collected from a nearshore, randomized, bottom longline survey. Age composition of the fishery-independent catch indicates low mortality of fish age 6 and above and confirms the effectiveness of the federal fishing moratorium. Bottom longline surveys may be a cost-effective method for developing fishery-independent indices for red drum provided additional effort can be added to nearshore waters (<20 m depth). As with most stocks under harvest bans, effective monitoring of the recovery of red drum will require the development of fishery-independent indices. With limited economic incentive to evaluate non-exploited stocks, the most cost-effective approach to developing such monitoring is expansion of existing fishery independent surveys. We examine this possibility for red drum in the Gulf of Mexico and recommend the bottom longline survey conducted by the National Marine Fisheries Service expand effort in nearshore areas to allow for the development of long-term abundance indices for red drum.