Spawning and Embryonic Development of the Least Brook Lamprey (Lampetra aepyptera)

Development of the gametes and early embryo in the Maryland brook lamprey (Lampetra aepyptera, sup.)

The purpose of this research was to identify the reproductive biology in the yellow rasbora ( Rasbora lateristriata ) in habitat of the Ngrancah River. To identify spawning events and embryo development, direct observation was employed during the spawning season in their natural environment, and then fertilized egg was incubated insitu. Spawning seasons underwent correspond to the end of rainy season and early dry season which characterized by clean freshly water and low temperature. The result showed that during spawning season, the broodfish migrated from Sermo Reservoir upward to the main river to find out the spawning site. In the early morning between 03.00 and 05.00 AM, the broodstock moved to the spawning site, then making aggregation and both female and male released their gametes in the shallower place. The aggregations were consisting around of 1 female and 3 males. The fertilized eggs would cleavage, and then embryo developed and yolk sac larval hatched within 23 hours at 27 o C. The knowledge about spawning events of yellow rasbora may be used for improved management tools in the future.

Embryonic development of haploid, triploid, gynogenetic diploid and normal diploid Japanese flounder (Paralichthys olivaceus) were observed at a water temperature of(16±0.5)℃, pH value of 8.0-8.3, and a salinity of 30.2. A high frequency of abnormality, particularly body flexion, the organ differentiation, the fertilizing rate, the rate of abnormality and the hatching rate was found in the haploid embryos. The embryos of gynogenetic diploid and triploid had basically the same process with the normal diploid embryos, as the zygotes developed through multicelled stage, blastula stage, gastrula stage, neurula stage, yolk plug formation stage, Kupffer's vesicle stage, tailbud stage, eye len formation stage, heart beating stage, hatching stage and hatched successfully. There were no significant differences in embryonic development among gynogenetic diploid, triploid and normal haploid individuals. However, different time of every stage was found in embryonic development among gynogenetic dipbid, triploid and haploid individuals. It took about 61 hours to hatch for the control diploid. For gynogenetic diploid and triploid, however, it took 66 hours 30 minutes and 67 hours 50 minutes to hatch, respectively, about 10% longer than the developmental time of the control diploid. Noticeably, the gynogenetic diploid and triploid had a- bout 25% longer than the control diploid at the multicelled stage. The hatching rate of (16.5±2.2)% and abnormity of (97.2±1.6)% happened to the haploid. The hatching rate of (85.6±3.0)% and (82.3±3.1)% occurred in both gynogenetic diploid and triploid with the abnormality of (13.2±2.3)% and (16.3±2.5)% respectively, no significant differences between gynogenetic diploid and triploid. But compared with the control dip- bid, both gynogenetic diploid and triploid had a lower hatching rate and higher abnormality.

Bird embryogenesis takes place in a relatively protected environment that can be manipulated especially well in domestic fowl (chickens) where incubation has long been a commercial process. The embryonic developmental process has been shown to begin in the oviduct such that the embryo has attained either the blastodermal and/or gastrulation stage of development at oviposition. Bird embryos can be affected by "maternal effects," and by environmental conditions during the pre-incubation and incubation periods. "Maternal effects" has been described as an evolutionary mechanism that has provided the mother, by hormonal deposition into the yolk, with the potential to proactively influence the development of her progeny by exposing them to her particular hormonal pattern in such a manner as to influence their ability to cope with the expected wide range of environmental conditions that may occur post-hatching. Another important aspect of "maternal effects" is the effect of the maternal nutrient intake on progeny traits. From a commercial broiler chicken production perspective, it has been established that greater cumulative nutrient intake by the hen during her pullet rearing phase prior to photostimulation resulted in faster growing broiler progeny. Generally, maternal effects on progeny, which have both a genetic and an environmental component represented by yolk hormones deposition and embryo nutrient utilization, have an important effect on the development of a wide range of progeny traits. Furthermore, commercial embryo development during pre-incubation storage and incubation, as well as during incubation per se has been shown to largely depend upon temperature, while other environmental factors that include egg position during storage, and the amount of H2O and CO2 lost by the egg and the subsequent effect on albumen pH and height during storage have become important environmental factors to be considered for successful embryogenesis under commercial conditions. Manipulating environmental temperature during the period of egg storage, during the intermediate pre-incubation period, and incubation period per se has been found to significantly affect embryo development, hatching progress, chick quality at hatching, and chick development post-hatching. These temperature manipulations have also been shown to affect the acquisition of thermotolerance to subsequent post-hatching thermal challenge. This chapter will focus on: a. "maternal effects" on embryo and post-hatching development; b. environmental effects during the post-ovipositional period of egg storage, the intermediate pre-incubation period, and incubation period per se on chick embryogenesis and subsequent post-hatching growth and development; and c. effects of temperature manipulations during the pre-incubation and incubation periods on acquisition of thermotolerance and development of secondary sexual characteristics in broiler chickens.

Dead lake trout (Salvelinus namaycush) killed by sea lamprey ( Petromyzon marinus) were collected from the bottom of Lake Ontario using bottom trawls. The number of dead lake trout per hectare could be predicted from the number of type A-1 sea lamprey marks observed on live fish in September gillnet surveys ( r 2 = 0.60, P 0.05) from those of live fish with A-1 marks in 5 of 6 years where compar- isons could be made. Compared with Lake Superior strain lake trout, Seneca Lake strain fish were only 0.41 times as likely to be attacked by sea lamprey and were less likely to die from an attack (both differences P 0,05) de celle observee chez les poissons vivants portant des cicatrices A-1, pour 5 des 6 annees ou une telle comparaison etait possible. La probabilite qu'un touladi de la souche du lac Seneca soit attaque par une lamproie equivalait a seulement 0,41 fois la probabilite qu'un tou- ladi de la souche du lac Superieur subisse le meme sort, et les attaques etaient moins souvent mortelles dans le premier cas ( P < 0,05 pour les deux differences). Les estimations prudentes du nombre de touladis tues par les lamproies marines dans le sud du lac Ontario entre octobre et la mi-novembre vont de 17 000 en 1988 a 121 000 en 1984. (Traduit par la Redaction)

At present five species of Petromyzonidae are found in the Great Lakes region. Of these, three are parasitic: Petromyzon marinus, Ichthyomyzon unicuspis, and I. castaneus; two are nonparasitic: I. fossor and Lethenteron lamottenii. It is quite possible that a nonparasitic sixth species, Lampetra aepyptera, could be found in the Lake Erie basin.Key words: lampreys, Great Lakes, keys, P. marinus, abnormality, L. lamottenii, gigantism

Embryonic development depends on an enormous amount of signaling events between a continuously growing number of cells. According to the classical view, signal transduction is based on either simple diffusion, trans­cytosis or migrating cells. Very recently the existence of filopodia-like protrusions has been proposed as a novel mechanism of long-range intercellular signaling during chick somite and limb development. Analogous thinner structures called cytonemes play a role in the development of Drosophila melanogaster , as well. The present study gives new insight into this problem by adding important information using scanning electron microscopy (SEM). Early chick embryos between stages 4 and 5 (representing late gastrulation and early neurula­tion) were dissected, fixed and critical-point dried and were then fractured in several steps, each step followed by platinum/palladium coating and analysis by SEM. Fracturing was carried out sequentially in the same specimens at different anterior-posterior levels anterior to the primitive node and the ultrastructure of the embryonic disc was analysed with special emphasis on cellular processes. We found cell protrusions of different shape and size in all three layers (mesoderm, epiblast, and hypoblast) of the early embryonic discs. They were most abundant and prominent between the mesodermal cells but also seen in other layers as well as between layers. These protru­sions can be roughly classified into cytoplasmic bridges with mid-bodies, cilia-like protrusions, as well as filopo­dia-like protrusions. As previously shown, cilia of different length are present on the apical surface of epiblast and hypoblast cells. Similarly a plethora of variable protrusions with or without mid-bodies are seen between neigh­bouring cells within embryonic layers. Unexpectedly, we found that cells of the mesodermal layer form a dense net of filopodia-like contacts with the epithelial cells of the epiblast. Our data prove that filopodia-like protrusions are present at earlier developmental stages than previously shown. Their abundance indicates a major role in the intercellular communication during early chick embryonic devel­opment and may provide a structural basis of cell-to-cell communication during gastrulation and early neurula­tion in the chick.

Little is known about nitrogenous waste (N waste) handling and excretion (JN waste) during the complex life cycle of the sea lamprey (Petromyzon marinus), an extant jawless fish that undergoes a complete metamorphosis from a filter-feeding larva (ammocoete) into a parasitic juvenile that feeds on the blood of larger, jawed fishes. Here, we investigate the ammonia- and urea-handling profiles of sea lampreys before, during, and after metamorphosis. The rates of ammonia excretion (Jamm) and urea excretion (Jurea) significantly decreased after the onset of metamorphosis, with the lowest rates observed during midmetamorphosis. Near the completion of metamorphosis, rates of JN waste () significantly increased as sea lampreys entered the juvenile period. Feeding juvenile lampreys had greater than 10- to 15-fold higher Jamm and fivefold higher Jurea compared to nonfed juveniles, which corresponded to higher postprandial (postfeeding) concentrations of plasma ammonia and urea. The routes of Jamm and Jurea completely diverged following metamorphosis. In larvae, Jamm was equally split between branchial (gills) and extrabranchial (skin plus renal) pathways, but following metamorphosis, >80% of ammonia was excreted via the gills in nonfeeding juvenile lampreys, and >95% of ammonia was excreted via the gills in adult sea lampreys. Urea, on the other hand, was predominantly excreted via extrabranchial routes and, to a lesser extent, the gills in larvae and in nonfeeding juveniles. In adults, however, virtually all urea was excreted via urine. Reverse transcription polymerase chain reaction and in silico analyses also indicated that a urea transporter encoded by a slc4a2-like gene is present in lampreys. The branchial expression of this transporter is modulated throughout sea lamprey life history, as it is higher in the larvae and steadily decreases until the adult stage. We conclude that the divergent pathways of Jamm and Jurea during the sea lamprey life cycle reflect changes in their habitat, lifestyle, and diet. Further, the near-complete reliance on renal routes for Jurea in adult sea lampreys is unique among fishes and may reflect the ancestral condition of how this N waste product was handled and excreted by the earliest vertebrates.

The half-striped Barb Puntius semifasciolatus (Gunther, 1868) is a small native freshwater fish inhabiting in brooks and small lakes of the western Taiwan. Due to environmental deterioration resulted from water pollution, habitat destruction, and introduction of exotic fishes, its population has been gradually declining and becoming rare or extinct in many parts of its original ranges. We induced spawning of the fish in the laboratory with injecting a mixed solution of grounded carp's pituitary glands and LRHA, and then, observed its spawning habit and examined its embryonic and larval developments at water temperatures of 26-28℃. The fertilized eggs had diameters of 1.2 mm in average. They developed to the stages of gastrula at 4-5 HAS (hours after spawning) and of embryos with myotome at 8-9 HAS and with heart beats and otoliths at 10-11 HAS. The larvae were hatched at 19-22 HAS. Newly hatched yolk- sac larvae had total lengths at an average of about 3.5 mm. The larvae started feeding on 3 DAH (days after hatching), and had well developed dorsal and anal fins on 10 DAH, pelvic fins on 20 DAH, and scales on 30 DAH.

OZET Bu calismada, dollenmis japon baligi yumurtalarindaki (Carassius sp.) embriyolojik ve larval gelisim incelenmistir. Istanbul Universitesi Su Urunleri Fakultesi Akvaryum Baliklari Yetistiriciligi Laboratuvari'nda 24 °C lik su sicakligi ve 7,1-7,4 pH da elde edilen dollenmis yumurtalardaki embriyolojik gelisim incelenmistir. Yapilan olcumlerde; japon baliginin yeni dollenmis yumurtalarinin yuvarlak, seffaf renkte ve 1,4-1,6 mm capinda oldugu, yumurtadan cikan keseli larvalarin ise saydam ve boy ortalamasinin 4,3-4,4 mm oldugu tespit edilmistir. Dollenmis yumurtalarda ilk 2 saatlik surede perivitellin boslugun olustugu, 2,5 saatin sonunda mitoz bolunmenin gerceklestigi, 7. saatte morula safhasinin basladigi ve blastula donemindeki (7,5 saat) yumurtada blastodermin periblasti olusturdugu gorulmustur. 19. saatin sonunda gastrula safhasi devam etmistir. 21.saatte vitellus uzerinde goz vezikulleri olusmus ve 26. saatte kuyruk somitleri ile pigmentasyon olusmaya baslamistir. 70. saate embriyo hareket etmistir. Butun bu gelisim safhalarindan sonra larvanin yumurtadan cikisi 73. saatte gerceklesmistir. 76. saatte vitellus cekilmeye baslamis ve kuyruk yuzgeci belirgin hale gelmistir. Larvalarda 81. saatte vitellus cekilmis, hava kesesi olusmus ve agiz acikligi henuz gorulmemistir. 82. saatte ic organlar ve yuzgec olusumlari belirgin hale gelmis ve agiz acikligi olusmaya baslamistir. Anahtar Kelimeler: Japon baligi, Carassius sp., embriyolojik ve larval gelisim. INVESTIGATION OF EMBRYOLOGIC AND LARVAL DEVELOPMENT ON THE GOLD FISH (Carassius sp.) ASTRACT Embryologic and larval developments of the fertilized gold fish (Carassius sp.) eggs were investigated in this research. Embryologic development of the fertilized eggs in the water of 24 °C and 7.1-7.4 pH obtained aquarium laboratory of the Fisheries Faculty, istanbul University were completed at 73 hours. The new fertilized gold fish eggs, were found round, transparent colour and 1.4-1.6 mm diameter, the newly hatched larva were determined transparent and 4.3-4.4 mm in the measurements. During the first 2 hours perivitellin has been occured and after that 2.5 hours mytosis stage were conducted and morula stage was started in first 7 hours. In blastula stage (7.5 hours) periblast was beeing by blastoderm and gastrula stage was followed. Eyes vesiculles were occured in 21 hours, caudal sommits and pigmentation in 26 hours. Embrio was mooved in 70. hours and fry was hatched in 73 hours. Vittelus absorbed by the larvae in 76. hours and caudal fin was occured. Vitellus absorbtion was completed and swim blader was occured in larvae but nouth opening was not shown in 81. hours. Visceral organ and fins were shown and mouth oppening was appear in 82 hours. As a result, during the larval development period of gold fish environmental conditions were effect embryologic and larval development and breeding of the fish. Key Words: Gold fish, Carassius sp., embryologic and larval development.

The internal quality of eggs is critical for human consumption and embryonic development. However, microorganisms inside eggs have not been thoroughly investigated for their roles in determining the egg's internal quality. Here, a total of 21 hens were selected from more than 1,000 chickens based on their hatching results and were divided into high- and low-hatchability groups. Then, we collected 72 eggs from these 21 hens to obtain egg whites and yolks, including 54 fresh eggs and 18 eggs after 12 days of incubation. We characterized the microbial composition of egg yolks and whites, the microbial change along incubation, and differences in microbial abundance between the high- and low-hatchability groups. The results indicated that egg whites are not sterile. Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes were the dominant phyla in egg yolk and white. There was a large difference in the microbial composition between egg whites and yolks, and this difference increased after 12 days of incubation. Egg whites have lower microbial diversity than egg yolks owing to the presence of antibacterial substances such as lysozyme in the egg white. After a 12-day incubation, the microbial diversity decreased in egg whites but increased slightly in egg yolks. Meanwhile, the microbes in egg white can migrate to egg yolk during incubation. Additionally, Genus Muribaculaceae was identified as a biomarker in egg yolks incubated for 12 days and was more often detected in healthy groups. On the contrary, more genus Rothia were found in the fresh egg yolk of the low hatchability groups and was considered to have low virulence. These findings shed light on the composition and differences in microbiota between egg yolks and whites and may open new avenues for studying embryonic development in chickens.

The sea lamprey (Petromyzon marinus) is widely distributed in the Great Lakes but it is absent from or scarce in large parts of the watershed. Since 1957, larval sea lampreys have been detected in only 433 (7.5%) of the 5747 streams in the Great Lakes basin. Parasitic-phase sea lampreys range throughout the lakes, wherever suitable host fishes occur, but probably do not inhabit the western and central basins of Lake Erie to any great extent during summer. Many environmental conditions influence the distribution of sea lampreys. Streamflow and water temperature are of major importance in attracting spawning runs to streams. The dispersal of spawning adults within streams is influenced mainly by blockages, water temperature, current, bottom type, and the presence of inland lakes. Water temperature is probably the most important factor affecting the development and survival of embryos. The distribution of larval lampreys is limited primarily by barriers that block adult spawning runs, warm temperatures, low and unstable flows, hard stream bottom, and pollution; nonetheless, larvae have been found in a wide range of habitats exhibiting these conditions. Interconnecting waterways and attachment to fishes and boats are considered major factors in the lake movements of parasitic-phase lampreys.Key words: sea lamprey, Petromyzon marinus; Great Lakes, geographic distribution, influences, movement, spawning, larvae, parasitic, control

In mammals, epigenetic markers are globally rearranged after fertilization: while gametes carry special epigenetic signatures and a unique nuclear organization, they attain embryo-specific patterns after fertilization. This “reprogramming” is promoted by the intimate contact between the parental inherited genomes and the oocyte cytoplasm over the first cell cycles of development. Interestingly, histone post-translational modifications (PTMs) are among the factors involved in this reprogramming. During the last few years, many studies focusing on epigenetic modifications have indeed shown that, immediately after fertilization, different histone PTM profiles create an asymmetry between the two parental genomes, although both parental genomes undergo global hyperacetylation and hypomethylation. Thereafter, histone PTMs reprogramming goes on (Beaujean et al., MRD 2014). It is hypothesized that this PTMs reprogramming is required for the embryonic genome activation (EGA). Recently, we for example put forward the importance of the PRC1 complex that binds H3K27me3, for proper EGA and development beyond the two-cell stage (Posfai et al., 2012). By the stage of implantation (blastocyst stage) two cell subpopulations forms: an outer layer of epithelial trophectoderm cells (TE) and the inner cell mass (ICM) located eccentrically within the blastocoelic cavity. Remarkably, some histone PTMs have been found to differ between the ICM vs. TE and to correlate with specific gene expression in each of these cell types (Dahl et al., 2010; Vermilyea et al., 2009). On the other hand, it is well known that diverse parts of the genome have different types of chromatin configuration depending on their function (centromeric and telomeric heterochromatin for instance). Interestingly, the mouse embryo presents a unique organization of the peri-centromeric heterochromatin that locates around the nucleoli. This configuration is rapidly acquired in the maternal pronucleus and more progressively in the paternal one (Martin et al., 2006; Aguirre-Lavin et al., 2012), probably due to the specific epigenetic marks present only in the paternal chromatin. During the 2-cell stage, dissociation of pericentromeric heterochromatin from nucleoli begins, concomitantly with the major phase of embryonic genome activation, although the importance of this remodeling is not yet well understood. Remarkably, it however seems that transcripts generated by pericentromeric satellite repeats are involved in this event and that interference with this phenomenon results in developmental arrest (Probst et al., 2010; Santenard et al., 2010; Fulka &amp; Langerova 2014). Altogether, it suggests that histone PTMs may be closely correlated with the formation of a transcriptionally active or repressive state during early embryonic development and that they can modify chromatin organization and nuclear architecture during mouse embryonic development. It should also be mentioned that knock-outs of several histone modification enzymes have underlined the importance of PTMs during preimplantation development.

I. INTRODUCTION The body plan of the Caenorhabditis elegans embryo is established during the first few cleavages. The reproducible orientations of these cleavages coupled with asymmetric localization of cytoplasmic components initiate processes that establish the three principal axes of the body and set the fates of the six founder cells. In this chapter, we review the current understanding of mechanisms controlling the early cleavages, and we address the following issues: (1) when and how embryonic polarity is established, (2) how cytoplasmic factors are differentially partitioned along an axis, and (3) how spindle positioning is controlled to generate cells of the correct sizes, in the correct positions, and with the correct contents. A. Overview of Embryogenesis For detailed descriptions of C. elegans embryogenesis, see Sulston et al. (1983), which describes the entire embryonic lineage, and Wood (1988) and Strome (1989). It takes 14 hours at 20°C for a newly fertilized embryo to complete embryogenesis and hatch from its eggshell into a juvenile worm. During the first few hours, the embryo undergoes a series of four unequal divisions, to produce five somatic founder cells (AB, E, MS, C, and D) and the primordial germ cell (P 4 ) by the 28-cell stage (Figs. 1 and 2a–i). Gastrulation begins at the 28-cell stage when the two daughters of E move to the interior of the embryo (Fig. 2i), followed later by P 4 and some of the descendants of MS, C, D, and AB. These cell movements, coupled with continued proliferation, result in a generally...

Lampreys belong to the superclass Cyclostomata and represent the most ancient group of vertebrates. Existing for over 360 million years, they are known as living fossils due to their many evolutionally conserved features. They are not only a keystone species for studying the origin and evolution of vertebrates, but also one of the best models for researching vertebrate embryonic development and organ differentiation. From the perspective of genetic information, the lamprey genome remains primitive compared with that of other higher vertebrates, and possesses abundant functional genes. Through scientific and technological progress, scientists have conducted in-depth studies on the nervous, endocrine, and immune systems of lampreys. Such research has significance for understanding and revealing the origin and evolution of vertebrates, and could contribute to a greater understanding of human diseases and treatments. This review presents the current progress and significance of lamprey research.