Genetic Population Structure and Gene Flow in the Atlantic Cod Gadus Morhua: A Comparison of Allozyme and Nuclear RFLP Loci

High levels of gene flow have been implicated in producing uniform patterns of allozyme variation among populations of many marine fish species. We have examined whether gene flow is responsible for the limited population structure in the Atlantic cod, Gadus morhua L., by comparing the previously published patterns of variation at 10 allozyme loci to 17 nuclear restriction fragment length polymorphism (RFLP) loci scored by 11 anonymous cDNA clones. Unlike the allozyme loci, highly significant differences were observed among all populations at the DNA markers in a pattern consistent with an isolation-by-distance model of population structure. The magnitude of allele frequency variation at the nuclear RFLP loci significantly exceeded that observed at the protein loci (χ(2) = 24.6, d.f. = 5, P < 0.001). Estimates of gene flow from the private alleles method were similar for the allozymes and nuclear RFLPs. From the infinite island model, however, estimates of gene flow from the DNA markers were fivefold lower than indicated by the proteins. The discrepancy between gene flow estimates, combined with the observation of a large excess of rare RFLP alleles, suggests that the Atlantic cod has undergone a recent expansion in population size and that populations are significantly displaced from equilibrium. Because gene flow is a process that affects all loci equally, the heterogeneity observed among populations at the DNA level eliminates gene flow as the explanation for the homogeneous allozyme patterns. Our results suggest that a recent origin of cod populations has acted to constrain the extent of population differentiation observed at weakly polymorphic loci and implicate a role for selection in affecting the distribution of protein variation among natural populations in this species.     

Evolutionary and Functional Aspects of Pituitary Gonadotropins in the Green Turtle, Chelonia Mydas

Information on the pituitary gonadotropins in Chelonia mydasrepresents some of the most complete data available for anyreptile and thus provides an important basis for evaluatingevolutionary processes in tetrapod endocrine physiology. Thetwo gonadotropins isolated from Chelonia pituitary glands showclear chemical and immunological homologies to mammalian follicle-stimulatinghormone (FSH) and luteinizing hormone (LH). However, receptorstudies and biological tests indicate that the functions ofthese hormones may be different in turtles and mammals. In particular,Chelonia LH shows an unusual ability to interact with FSH receptorsites and to stimulate physiological functions normally attributedto FSH. Results with Chelonia LH demonstrate that errors mayarise from using mammalian hormones to investigate reproductionin turtles. Measurements of endogenous gonadotropin levels inthe plasma of breeding and nesting Chelonia provide a differentperspective of the potential roles of the FSH and LH from thatobtained in physiological tests. In particular, FSH and LH secretionare markedly dissociated during the nesting cycle; FSH has onlya transient peak during oviposition, whereas LH, along withprogesterone, displays a pronounced "ovulatory" surge in theday following nesting. Preliminary studies with synthetic gonadotropicreleasing factors in Chelonia suggest that these may be usefulin inducing reproductive changes.     

Geographic Structure of Mitochondrial and Nuclear Gene Polymorphisms in Australian Green Turtle Populations and Male-Biased Gene Flow

The genetic structure of green turtle (Chelonia mydas) rookeries located around the Australian coast was assessed by (1) comparing the structure found within and among geographic regions, (2) comparing microsatellite loci vs. restriction fragment length polymorphism analyses of anonymous single copy nuclear DNA (ascnDNA) loci, and (3) comparing the structure found at nuclear DNA markers to that of previously analyzed mitochondrial (mtDNA) control region sequences. Significant genetic structure was observed over all regions at both sets of nuclear markers, though the microsatellite data provided greater resolution in identifying significant genetic differences in pairwise tests between regions. Inferences about population structure and migration rates from the microsatellite data varied depending on whether statistics were based on the stepwise mutation or infinite allele model, with the latter being more congruent with geography. Estimated rates of gene flow were generally higher than expected for nuclear DNA (nDNA) in comparison to mtDNA, and this difference was most pronounced in comparisons between the northern and southern Great Barrier Reef (GBR). The genetic data combined with results from physical tagging studies indicate that the lack of nuclear gene divergence through the GBR is likely due to the migration of sGBR turtles through the courtship area of the nGBR population, rather than male-biased dispersal. This example highlights the value of combining comparative studies of molecular variation with ecological data to infer population processes.     

Structure and Function of the Gastrointestinal Tract of the Green Turtle(Chelonia mydas) Hatchling

The gastrointestinal tracts of four Chelonia mydas hatchlings were examined at the anatomical, histological and ultrastructural level. Our results show that the gastrointestinal tract(GI) is composed by esophagus, stomach, small intestine(SI) and large intestine(LI), and histologically of mucosa, submucosa, muscularis externa(ME) and serosa. The esophagus is marked by conical papillae lined by keratinized stratified squamous epithelium, whereas the remaining GI by simple columnar epithelium; esophageal diverticulum is absent. The stomach covered with mucous granule cells, contains cardia, fundic regions and pylorus, which are separately characterized by cardiac glands, fundic glands and pyloric glands, and have the thickest submucosa and ME of the GI. The ME of the esophagus mainly consist of one layer of circular smooth muscle whereas the rest of GI of two layers, inner circular muscle and outer longitudinal muscle. The SI is slightly longer than the LI and the GI is approximately 5.11 times of the carapace length. The SI is lined with longitudinal zigzag folds and characterized by absorptive cells with longer and denser microvilli, whereas the LI by transversal folds, goblet cells and lymphoid nodules. Only intestinal glands appear in duodenum. Endocrine cells are observed in all sections of the GI and accounted for the largest proportion in duodenum. The results demonstrate a perfect combination of the structure and function of the GI and reveal that the digestion and absorption primarily occurs in the foregut. C. mydas hatchling may prefer carnivorous diet.     

Blood Gases,Biochemistry, and Hematology of Galapagos Green Turtles (Chelonia Mydas)

The green turtle, Chelonia mydas, is an endangered marine chelonian with a circum-global distribution. Reference blood parameter intervals have been published for some chelonian species, but baseline hematology, biochemical, and blood gas values are lacking from the Galapagos sea turtles. Analyses were done on blood samples drawn from 28 green turtles captured in two foraging locations on San Cristóbal Island (14 from each site). Of these turtles, 20 were immature and of unknown sex; the other eight were males (five mature, three immature). A portable blood analyzer (iSTAT) was used to obtain near immediate field results for pH, lactate, pO₂, pCO₂, HCO₃ ⁻, Hct, Hb, Na, K, iCa, and Glu. Parameter values affected by temperature were corrected in two ways: (1) with standard formulas; and (2) with auto-corrections made by the iSTAT. The two methods yielded clinically equivalent results. Standard laboratory hematology techniques were employed for the red and white blood cell counts and the hematocrit determination, which was also compared to the hematocrit values generated by the iSTAT. Of all blood analytes, only lactate concentrations were positively correlated with body size. All other values showed no significant difference between the two sample locations nor were they correlated with body size or internal temperature. For hematocrit count, the iSTAT blood analyzer yielded results indistinguishable from those obtained with high-speed centrifugation. The values reported in this study provide baseline data that may be useful in comparisons among populations and in detecting changes in health status among Galapagos sea turtles. The findings might also be helpful in future efforts to demonstrate associations between specific biochemical parameters and disease.     

118 A Nutritional Analysis of the Turf Algal Diet and Fecal Pellets of The Green Turtle,Chelonia Mydas L

In 1978, the green turtle, Chelonia mydas, was listed as threatened in the United States under the Endangered Species Act. Any knowledge gained from an understanding of the diet and how it affects this species' ability to survive is crucial. Turf algae, the primary component of the diet of Chelonia mydas, and turtle fecal pellets were collected from Kaloko‐Honokohau National Historical Park on the island of Hawaii at monthly intervals. The turf algae and fecal pellets were subjected to nutritional analyses for protein, carbohydrate, lipid, ash, and caloric content. The fecal pellets were higher in protein content than the turf algae, which may be related to fermentation carried out by bacteria in the turtle hindgut that increases the amount of protein available for absorption. From the nutritional data, assimilation efficiencies were calculated for the green turtle.     

Amino Acid Sequence and Activity of Green Turtle (Chelonia mydas) Lysozyme

Green turtle lysozyme purified from egg white was sequenced and analyzed its activity. Lysozyme was reduced and pyridylethylated or carboxymethylated to digest with trypsin, chymotrypsin and V8 protease. The peptides yielded were purified by RP-HPLC and sequenced. Every trypsin peptide was overlapped by chymotrypsin peptides and V8 protease peptides. This lysozyme is composed of 130 amino acids including an insertion of a Gly residue between 47 and 48 residues when compared with chicken lysozyme. The amino acid substitutions were found at subsites E and F. Namely Phe34, Arg45, Thr47, and Arg114 were replaced by Tyr, Tyr, Pro, and Asn, respectively. The time course using N-acetylglucosamine pentamer as a substrate showed a reduction of the rate constant of glycosidic cleavage and transglycosylation and increase of binding free energy for subsite E, which proved the contribution of amino acids mentioned above for substrate binding at subsites E and F.     

Conservation Genetics of the East Pacific Green Turtle (Chelonia mydas) in Michoacan, Mexico

The main continental nesting rookeries of the east Pacific green turtle (EPGT), Chelonia mydas, on the Michoacan (Mexico) coast suffered drastic population declines following intense exploitation in the 1960s--1970s with annual abundance of nesting females plummeting from about 25,000 to an average of about 1400 between 1982 and 2001. Analyses of data from three nDNA microsatellite loci and 400 bp mtDNA control region sequences from a total of 123 nesting females sampled from four Michoacan rookeries found no evidence of population sub-structuring. The recent order of magnitude reduction in the population size shows no apparent impact on genetic diversity in either control region sequences (overall h = 0.48; pi = 0.0036) or microsatellite loci (overall Na = 20.8; Hexp = 0.895). Our estimates of annual effective female population size (Nef; from theta = 2Nemicron) of 1.9-2.3 x 10(3), in spite of being an order of magnitude below historical records, appear to be sufficient to allow recovery of this population without significant loss of genetic diversity. These findings highlight the importance of continued conservation to reverse the decline of this population before it becomes vulnerable to genetic erosion.     

The Complete Amino Acid Sequence of Green Turtle (Chelonia mydas) Egg White Ribonuclease

Egg white ribonuclease was first found in green turtle eggs. This enzyme has been purified by CM-toyopearl cation exchange. Two isoforms (GTRNase-1 and GTRNase-2) were further separated by RP-HPLC, with the same M.W. (13 kDa) and activity. These isoforms carried one amino acid exchange of Ser and Leu at the position 37. The N-terminal sequence, ETRYEKF, was determined for the transblotted protein. Internal sequences were analyzed by protein sequencer and ESI-Q-TOF mass spectrometry for tryptic peptides (Ts). The overlapping sequences were obtained from chymotryptic peptides, CNBr fragments and ISD-MS/MS analysis. The C-terminal Ile was identified by CPase-Y. The established sequence composed of 119 residues with the molecular mass of 12,942.1 Da for GTRNase-1 and 12,967.8 Da for GTRNase-2. The comparison of sequence with known pancreatic RNases, 27 positions including catalytic residues at the position 11 and 114 were conserved. Also basic residues contributed to phosphate binding residues were conserved with the exception of Lys 66. One insertion at the position 14, and 3 deletions at the position-1, between position 64–65, and 110 and 111 were found. Two Cys residues at position 65 and 72 that form a disulfide bond in mammalian RNase were deleted and exchanged. All these difference in the sequence were similar to reptile pancreatic RNase.Data deposition: The sequence reported in this paper has been submitted to the UniProt Knowledgebase under accession No. P84844.     

The feminizing effect of metabolic heating in Green Turtle (Chelonia mydas) clutches in the eastern Mediterranean

Metabolic heating has been poorly investigated in eastern Mediterranean coastline of Turkey, which host some of the most important Green Turtle (Chelonia mydas) nesting sites in the Mediterranean. We studied the effects of clutch size and embryo numbers on nest temperature and discuss the feminizing effect of metabolic heating. Two test sites were conducted in Sugözü Beaches (Turkey). Data loggers were placed in eight nests with different clutch sizes. Nest temperature was strongly correlated with embryo numbers and metabolic heating produced by embryos was calculated to be 0.019°C per late stage embryo and 0.020°C per hatchling. Metabolic heating was calculated to be 0.6°C in the middle third of the incubation period during which sex is determined. It was estimated that metabolic heating increased 10.4% of female hatchlings. The heat produced by embryos should be taken into consideration while estimating sex ratios indirectly by nest and sand temperatures. Additionally, the metabolic heating value should be known for conservation measures, such as nest relocation, dividing the nest for controlling nest temperature, especially related to climate change.     

The stomach content of a Mediterranean Monk Seal (Monachus monachus): finding of Green Turtle (Chelonia mydas) remains

The stomach contents of an adult Mediterranean Monk Seal (Monachus monachus) found stranded on the Turkish eastern Mediterranean coast near Antalya in May 2013 were analysed. In total, 69 individual food items were counted and nine taxa were identified to species or family level. Of the identified taxa, Sparidae was the most highly represented family of prey fish, and one cephalopod species, Octopus vulgaris, was found. Ariosoma balearicum and Argyrosomus regius were encountered for the first time in the diet of a Monk Seal in the Mediterranean. Several body parts (three heads, six forelimbs, neck bones and fractured upper forelimb bones) of Green Turtles (Chelonia mydas) were also identified, which is the first record of this species in the Monk Seal’s diet.     

Nesting Phenology of Marine Turtles: Insights from a Regional Comparative Analysis on Green Turtle (Chelonia mydas)

Changes in phenology, the timing of seasonal activities, are among the most frequently observed responses to environmental disturbances and in marine species are known to occur in response to climate changes that directly affects ocean temperature, biogeochemical composition and sea level. We examined nesting seasonality data from long-term studies at 8 green turtle (Chelonia mydas) rookeries that include 21 specific nesting sites in the South-West Indian Ocean (SWIO). We demonstrated that temperature drives patterns of nesting seasonality at the regional scale. We found a significant correlation between mean annual Sea Surface Temperature (SST) and dates of peak nesting with rookeries exposed to higher SST having a delayed nesting peak. This supports the hypothesis that temperature is the main factor determining peak nesting dates. We also demonstrated a spatial synchrony in nesting activity amongst multiple rookeries in the northern part of the SWIO (Aldabra, Glorieuses, Mohéli, Mayotte) but not with the eastern and southern rookeries (Europa, Tromelin), differences which could be attributed to females with sharply different adult foraging conditions. However, we did not detect a temporal trend in the nesting peak date over the study period or an inter-annual relation between nesting peak date and SST. The findings of our study provide a better understanding of the processes that drive marine species phenology. The findings will also help to predict their ability to cope with climate change and other environmental perturbations. Despite demonstrating this spatial shift in nesting phenology, no trend in the alteration of nesting dates over more than 20 years was found.     

Genetic Structure and Gene Flow in Elymus glaucus (blue wildrye): Implications for Native Grassland Restoration

Interest in using native grass species for restoration is increasing, yet little is known about the ecology and genetics of native grass populations or the spatial scales over which seed can be transferred and successfully grown. The purpose of this study was to investigate the genetic structure within and among populations of Elymus glaucus in order to make some preliminary recommendations for the transfer and use of this species in revegetation and restoration projects. Twenty populations from California, Oregon, and Washington were analyzed for allozyme genotype at 20 loci, and patterns of variation within and among populations were determined. Allozyme variation at the species level was high, with 80% of the loci polymorphic and an average expected heterozygosity (an index of genetic diversity) of 0.194. All but two of the populations showed some level of polymorphism. A high degree of population differentiation was found, with 54.9% of the variation at allozyme loci partitioned among populations (F_st= 0.549). A lesser degree of genetic differentiation among closely spaced subpopulations within one of the populations was also demonstrated (F_st= 0.124). Self-pollination and the patchy natural distribution of the species both likely contribute to the low level of gene flow (N_m= 0.205) that was estimated. Zones developed for the transfer of seed of commercial conifer species may be inappropriate for transfer of E. glaucus germplasm because conifer species are characterized by high levels of gene flow. Limited gene flow in E. glaucus can facilitate the divergence of populations over relatively small spatial scales. This genetic differentiation can be due to random genetic drift, localized selective pressures, or both. In order to minimize the chances of planting poorly adapted germplasm, seed of E. glaucus may need to be collected in close proximity to the proposed restoration site.     

Genetic Diversity and Population Structure for the Conservation of Giant Spiny Frog(Quasipaa spinosa) Using Microsatellite Loci and Mitochondrial DNA

The giant spiny frog(Quasipaa spinosa) is an endangered species with a relatively small distribution limited to southern China and Northern Vietnam. This species is becoming increasingly threatened because of over-exploitation and habitat degradation. This study provides data on the genetic diversity and population genetic structure of the giant spiny frog to facilitate the further development of effective conservation recommendations for this economically important but threatened species. We examined 10 species-specific microsatellite loci and Cyt b genes(562 bp) collected from 13 wild populations across the entire range of this species. Results of 10 microsatellite loci analysis showed a generally high level of genetic diversity. Moreover, the genetic differentiation among all 12 populations was moderate to large(overall F_(ST) = 0.1057). A total of 51 haplotypes were identified for Cyt b, which suggests high haplotype nucleotide diversities. Phylogeographic and population structure analyses using both DNA markers suggested that the wild giant spiny frog can be divided into four distinct major clades, i.e., Northern Vietnam, Western China, Central China, and Eastern China. The clades with significant genetic divergence are reproductively isolated, as evidenced by a high number of private alleles and strong incidence of failed amplification in microsatellite loci. Our research, coupled with other studies, suggests that Q. spinosa might be a species complex within which no detectable morphological variation has been revealed. The four phylogenetic clades and some subclades with distinct geographical distribution should be regarded as independent management units for conservation purposes.     

Anonymous Marker Loci within 400 kb of HLA-A Generate Haplotypes in Linkage Disequilibrium with the Hemochromatosis Gene (HFE)

The hemochromatosis gene (HFE) maps to 6p21.3 and is less than 1 cM from the HLA class I genes; however, the precise physical location of the gene has remained elusive and controversial. The unambiguous identification of a crossover event within hemochromatosis families is very difficult; it is particularly hampered by the variability of the phenotypic expression as well as by the sex- and age-related penetrance of the disease. For these practical considerations, traditional linkage analysis could prove of limited value in further refining the extrapolated physical position of HFE. We therefore embarked upon a linkage-disequilibrium analysis of HFE and normal chromosomes from the Brittany population. In the present report, 66 hemochromatosis families yielding 151 hemochromatosis chromosomes and 182 normal chromosomes were RFLP-typed with a battery of probes, including two newly derived polymorphic markers from the 6.7 and HLA-F loci located 150 and 250 kb telomeric to HLA-A, respectively. The results suggest a strong peak of existing linkage disequilibrium focused within the i82-to-6.7 interval (approximately 250 kb). The zone of linkage disequilibrium is flanked by the i97 locus, positioned 30 kb proximal to i82, and the HLA-F gene, found 250 kb distal to HLA-A, markers of which display no significant association with HFE. These data support the possibility that HFE resides within the 400-kb expanse of DNA between i97 and HLA-F. Alternatively, the very tight association of HLA-A3 and allele 1 of the 6.7 locus, both of which are comprised by the major ancestral or founder HFE haplotype in Brittany, supports the possibility that the disease gene may reside immediately telomeric to the 6.7 locus within the linkage-disequilibrium zone. Additionally, hemochromatosis haplotypes possessing HLA-A11 and the low-frequency HLA-F polymorphism (allele 2) are supportive of a separate founder chromosome containing a second, independently arising mutant allele. Overall, the establishment of a likely “hemochromatosis critical region” centromeric boundary and the identification of a linkage-disequilibrium zone both significantly contribute to a reduction in the amount of DNA required to be searched for novel coding sequences constituting the HFE defect.     

羚牛的遗传多样性及其种群遗传结构分析

羚牛是亚洲大陆一种特有的大型珍稀动物,目前正面临着栖息地丧失、片段化和人类活动的严重威胁。为了有效地保护这种濒危动物,全面了解羚牛的种群结构、进化历史和整个分布区内遗传多样性的分布是至关重要的。本研究以mtDNA D-loop330bp基因片段为分子标记,比较分析了来自陕西秦岭、甘肃南部、四川岷山、邛崃山和云南贡山的40个样品的序列差异,根据分布特点将所采集到的羚牛分为3个地理单元,即秦岭、四川和云南。结果表明,在3个地理单元中存在4种单倍型,且地理单元间不存在共享单倍型,相互单倍型之间的平均序列差异为1.66％。进一步分析表明,3个地理单元间的基因流较低,存在着显的遗传分化 ,说明羚牛具有明显的系统地理分布格局。同时提出应将分布于秦岭山区、唐家河青川地区、天全以及云南贡山地区作为独立的管理单元分别加以保护。     

New Nuclear SNP Markers Unravel the Genetic Structure and Effective Population Size of Albacore Tuna (Thunnus alalunga)

In the present study we have investigated the population genetic structure of albacore (Thunnus alalunga, Bonnaterre 1788) and assessed the loss of genetic diversity, likely due to overfishing, of albacore population in the North Atlantic Ocean. For this purpose, 1,331 individuals from 26 worldwide locations were analyzed by genotyping 75 novel nuclear SNPs. Our results indicated the existence of four genetically homogeneous populations delimited within the Mediterranean Sea, the Atlantic Ocean, the Indian Ocean and the Pacific Ocean. Current definition of stocks allows the sustainable management of albacore since no stock includes more than one genetic entity. In addition, short- and long-term effective population sizes were estimated for the North Atlantic Ocean albacore population, and results showed no historical decline for this population. Therefore, the genetic diversity and, consequently, the adaptive potential of this population have not been significantly affected by overfishing.     

Dispersal and Diving Adjustments of the Green Turtle Chelonia mydas in Response to Dynamic Environmental Conditions during Post-Nesting Migration

In response to seasonality and spatial segregation of resources, sea turtles undertake long journeys between their nesting sites and foraging grounds. While satellite tracking has made it possible to outline their migration routes, we still have little knowledge of how they select their foraging grounds and adapt their migration to dynamic environmental conditions. Here, we analyzed the trajectories and diving behavior of 19 adult green turtles (Chelonia mydas) during their post-nesting migration from French Guiana and Suriname to their foraging grounds off the coast of Brazil. First Passage Time analysis was used to identify foraging areas located off Ceará state of Brazil, where the associated habitat corresponds to favorable conditions for seagrass growth, i.e. clear and shallow waters. The dispersal and diving patterns of the turtles revealed several behavioral adaptations to the strong hydrodynamic processes induced by both the North Brazil current and the Amazon River plume. All green turtles migrated south-eastward after the nesting season, confirming that they coped with the strong counter North Brazil current by using a tight corridor close to the shore. The time spent within the Amazon plume also altered the location of their feeding habitats as the longer individuals stayed within the plume, the sooner they initiated foraging. The green turtles performed deeper and shorter dives while crossing the mouth of the Amazon, a strategy which would help turtles avoid the most turbulent upper surface layers of the plume. These adjustments reveal the remarkable plasticity of this green turtle population when reducing energy costs induced by migration.     

Recent Demographic History and Present Fine-Scale Structure in the Northwest Atlantic Leatherback (Dermochelys coriacea) Turtle Population

The leatherback turtle Dermochelys coriacea is the most widely distributed sea turtle species in the world. It exhibits complex life traits: female homing and migration, migrations of juveniles and males that remain poorly known, and a strong climatic influence on resources, breeding success and sex-ratio. It is consequently challenging to understand population dynamics. Leatherbacks are critically endangered, yet the group from the Northwest Atlantic is currently considered to be under lower risk than other populations while hosting some of the largest rookeries. Here, we investigated the genetic diversity and the demographic history of contrasted rookeries from this group, namely two large nesting populations in French Guiana, and a smaller one in the French West Indies. We used 10 microsatellite loci, of which four are newly isolated, and mitochondrial DNA sequences of the control region and cytochrome b. Both mitochondrial and nuclear markers revealed that the Northwest Atlantic stock of leatherbacks derives from a single ancestral origin, but show current genetic structuration at the scale of nesting sites, with the maintenance of migrants amongst rookeries. Low nuclear genetic diversities are related to founder effects that followed consequent bottlenecks during the late Pleistocene/Holocene. Most probably in response to climatic oscillations, with a possible influence of early human hunting, female effective population sizes collapsed from 2 million to 200. Evidence of founder effects and high numbers of migrants make it possible to reconsider the population dynamics of the species, formerly considered as a metapopulation model: we propose a more relaxed island model, which we expect to be a key element in the currently observed recovering of populations. Although these Northwest Atlantic rookeries should be considered as a single evolutionary unit, we stress that local conservation efforts remain necessary since each nesting site hosts part of the genetic diversity and species history.     

Relationship between the major phosphorylated metabolic intermediates and oxygen affinity of whole blood in the loggerhead (Caretta caretta) and the Green Sea Turtle (Chelonia mydas) during development.

(1) 2,3-Diphosphoglyceric acid (2,3-DPG) is present in the erythrocytes (RBC) of the 68-day loggerhead turtle embryo and 44-day green sea turtle embryo at levels of 7.4 and 5.5 μmoles/ml of RBC, representing the major organic phosphate during the latter period of embryonic development. (2) Inositol pentaphosphate (IPP) is absent in the red blood cells of the embryos of both the loggerhead and green sea turtle. (3) Near equimolar amounts of 2,3-DPG and IPP are present in the erythrocytes of the adult loggerhead and green sea turtle. The total concentration of these two organic phosphates is approximately 0.75 μmoles/ml of RBC in the adult of both species. (4) There is a switch from embryonic to adult hemoglobin during development of these two species of turtles; the two embryonic bands have identical electrophoretic mobilities, whereas the two adult bands migrate differently on cellulose acetate at pH 8.6. (5) The whole blood oxygen affinity of the adult loggerhead and green sea turtle is 60.3 and 32.6 Torr, respectively. (6) The stripped adult hemoglobins in these two species of turtles show no change in oxygen affinity upon addition of 2,3-DPG, ATP, or IPP. (7) It therefore appears unlikely that whole blood oxygen affinity is controlled by organic phosphate modulation of hemoglobin function in these species of turtles.