The erythroid cells and haemoglobins of the chick embryo

The changes in the types of erythroid cells produced during embryogenesis of the chick have been correlated with the changes in the types of haemoglobins found in the embryo. Primitive erythroid cells constitute the only red blood cells of 2- to 5-day embryos. The first recognizable immature definitive erythroid cells appear in the embryonic circulation at 5 to 6 days and progressively replace the primitive cells, such that by 14 to 16 days the primitive cells constitute less than 1 % of the circulating erythroid cells. Primitive erythropoiesis is strikingly different from definitive erythropoiesis. At any one time point between 2 and 16 days, all of the isolated primitive cells appear, by morphological criteria, to be at the same stage of maturation, and, although variation in cell size is observed, for an individual maturation stage, the small cells are not more mature than the medium-size cells, nor are the large cells less mature than the medium or small cells. Maturing primitive erythroid cells undergo the progressive changes in cell structure characteristic of erythroid maturation in mammalian erythropoietic systems, but do so as a uniform cell population. Haemoglobin, isolated from primitive erythroid cells of 2- to 5-day embryos, shows two components on polyacrylamide gel electrophoresis, haemoglobin E and haemoglobin P. The haemoglobin E/P ratio is constant in lysates from 2- to 5-day embryos. A t 6 to 7 days when the first haemoglobinized immature definitive erythroid cells appear in the embryonic circulation, two new haemoglobin components are observed in lysates of erythroid cells. These two new haemoglobin components are electrophoretically and immunologically identical to the two haemoglobin components of adult chickens, haemoglobins A and D. As the definitive erythroid cells replace the primitive erythrocytes in the embryonic circulation, the haemoglobins A and D increase in amount and replace haemoglobin P. Haemoglobin P cannot be detected immunologically in erythroid cell lysates from 16-day embryos which contain less than 1 % primitive cells. In erythroid cell lysates from late embryos, which contained few, if any, primitive erythrocytes, a minor haemoglobin, electrophoretically similar to haemoglobin E on pH 10.3 polyacrylamide gels, is consistently observed. This component differs from haemoglobin E on pH 8.9 polyacrylmide gels, on Sephadex G-100 columns, on polyacrylamide gels of different porosities, and shows a reaction of only partial identity with haemoglobin E by two-dimensional immunodiffusion. This haemoglobin component, haemoglobin H, is detectable electrophoretically in lysates from 12-day embryos and immunologically in lysates from 8-day embryos. Haemoglobin H has not been observed in adult chickens. The switch from the production of primitive to definitive erythroid cells during development of the chick embryo is associated with the initiation of synthesis of three new haemoglobins, the two adult haemoglobins and haemoglobin H. The haemoglobin D /A ratio of adult chicken haemoglobin, determined from the ratio of gel scan peak masses, is 0.30. When haemoglobins D and A first appear in erythroid cell lysates from 6- to 7-day embryos, the haemoglobin D /A ratio is about 0.9. T he D/A ratio of lysates falls to 0.5 by 16 to 18 days, a time when 99 % of the erythroid cells of the embryo are mature definitive erythrocytes. However, the haemoglobin D /A ratio of lysates from late embryos and young chicks of 0.5 to 20 days of age is consistently greater than that of adult chicken haemoglobin. Definitive erythrocytes of chick embryos and young chicks appear to differ from definitive cells of adult chickens in at least two ways: the presence of haemoglobin H and the higher haemoglobin D/A ratio.

A review of blood substitutes: examining the history, clinical trial results, and ethics of hemoglobin-based oxygen carriers

The complications associated with acquiring and storing whole blood for transfusions have launched substantial efforts to develop a blood substitute. The history of these efforts involves a complicated mixture of science, ethics, and business. This review focuses on clinical trials of the three hemoglobin-based oxygen carriers (HBOC) that have progressed to Phase II or III clinical trials: He-mAssist (Baxter; Deerfield, IL, US), PolyHeme (Northfield; Evanston, IL, US), and Hemopure (Biopure; Cambridge, MA, US). Published animal studies and clinical trials carried out in a perioperative setting have demonstrated that these products successfully transport and deliver oxygen, but all may induce hypertension and lead to unexpectedly low cardiac outputs. Overall, these studies suggest that HBOCs resulted in only modest blood saving during and after surgery, no improvement in mortality and an increased incidence of adverse reactions. To date, the results from these perioperative studies have not led to regulatory approval. All three companies instead chose to focus their efforts on large trials of trauma patients in the pre-hospital setting.Baxter abandoned the development of HemAssist after a trial in the U.S. was prematurely halted when the first 100 patients showed significantly increased mortality rates as compared to patients treated with blood products. Northfield's PolyHeme trial demonstrated a non-significant trend towards increased mortality and a very modest reduction in the subsequent need for blood. The testing of Biopure's Hemopure for trauma patients has been halted for several years because of FDA concerns over trial design and study justification. Ethical concerns have also been raised regarding the design and implementation of all HBOC clinical trials.Thus, the available evidence suggests that HemAssist, Polyheme, and Hemopure are associated with a significant level of cardiovascular dysfunction. The next generation of HBOCs remains under development.

Hemoglobin loss from erythrocytes in vivo results from spleen-facilitated vesiculation

Previous studies have shown that approximately 20% of hemoglobin is lost from circulating red blood cells (RBCs), mainly during the second half of the cells' life span. Because hemoglobin-containing vesicles are known to circulate in plasma, these vesicles were isolated. Flow cytometry studies showed that most RBC-derived vesicles contain hemoglobin with all hemoglobin components present. The hemoglobin composition of the vesicles resembled that of old RBCs. RBC cohort studies using isotope-labeled glycine have been described, which showed a continuous presence of this label in hemoglobin degradation products. The label concentration of these products increased during the second half of the RBC life span, accompanied by a decrease within the RBC. It is concluded that the hemoglobin loss from circulating RBCs of all ages can be explained by shedding hemoglobin-containing vesicles. This loss occurs predominantly in older RBCs. Apparently the spleen facilitates this process since asplenia vesicle retention within RBCs of all ages has been described, accompanied by an increase in the percentage of total HbA(1). The present study shows that in old RBCs of asplenic individuals, the decrease of hemoglobin content per cell such as seen in old RBCs of control individuals is absent due to an increase in the absolute amount of HbA(1c) and HbA(1e2). It is concluded that hemoglobin-containing vesicles within old RBCs are "pitted" by the spleen.

Variation of Plasmodium falciparum msp1 block 2 and msp2 allele prevalence and of infection complexity in two neighbouring Senegalese villages with different transmission conditions

To investigate the impact of transmission on the development of immunity to malaria and on parasite diversity, longitudinal surveys have been conducted for several years in Dielmo and Ndiop, 2 neighbouring Senegalese villages with holo- and mesoendemic transmission conditions, respectively. We analysed Plasmodium falciparum msp1 block 2 and msp2 genotypes of isolates collected from 58% of the Dielmo villagers during the same week as those studied recently from Ndiop. Allele frequencies differed in both villages, indicating considerable microgeographical heterogeneity of parasite populations. The complexity of the infections, estimated using individual or combined msp1 and msp2 genotyping, in Dielmo was more than double that in Ndiop and it was age-dependent in Dielmo but not in Ndiop. Thus, this study confirmed the influence of age on the complexity of asymptomatic malaria infections in a holoendemic area. The age distribution of complexity in Dielmo substantiates the interpretation that the number of parasite types per isolate reflects acquired antiparasite immunity. This cross-sectional survey also confirms that the sickle cell trait has no impact on complexity but influences the distribution of P. falciparum genotypes.

Neuroglobin and other hexacoordinated hemoglobins show a weak temperature dependence of oxygen binding

Mouse and human neuroglobins, as well as the hemoglobins from Drosophila melanogaster and Arabidopsis thaliana, were recombinantly expressed in Escherichia coli, and their ligand-binding properties were studied versus temperature. These globins have a common feature of being hexacoordinated (via the distal histidine) under deoxy conditions, as evidenced by a large amplitude for the alpha absorption band at 560 nm and the Soret band at 426 nm. The transition from the hexacoordinated form to the CO bound species is slow, as expected for a replacement reaction Fe-His --> Fe --> FeCO. The intrinsic binding rates would indicate a high oxygen affinity for the pentacoordinated form, due to rapid association and slow (100 ms-1 s) dissociation. However, the competing protein ligand results in a much lower affinity, on the order of magnitude of 1 torr. In addition to decreasing the affinity for external ligand, the competitive internal ligand leads to a weaker observed temperature dependence of the ligand affinity, since the difference in equilibrium energy for the two ligands is much lower than that of ligand binding to pentacoordinated hemoglobin. This effect could be of biological relevance for certain organisms, since it could provide a globin with an oxygen affinity that is nearly independent of temperature.

Direct measurement of equilibrium constants for high-affinity hemoglobins

The biological functions of heme proteins are linked to their rate and affinity constants for ligand binding. Kinetic experiments are commonly used to measure equilibrium constants for traditional hemoglobins comprised of pentacoordinate ligand binding sites and simple bimolecular reaction schemes. However, kinetic methods do not always yield reliable equilibrium constants with more complex hemoglobins for which reaction mechanisms are not clearly understood. Furthermore, even where reaction mechanisms are clearly understood, it is very difficult to directly measure equilibrium constants for oxygen and carbon monoxide binding to high-affinity (K(D) << 1 micro M) hemoglobins. This work presents a method for direct measurement of equilibrium constants for high-affinity hemoglobins that utilizes a competition for ligands between the "target" protein and an array of "scavenger" hemoglobins with known affinities. This method is described for oxygen and carbon monoxide binding to two hexacoordinate hemoglobins: rice nonsymbiotic hemoglobin and Synechocystis hemoglobin. Our results demonstrate that although these proteins have different mechanisms for ligand binding, their affinities for oxygen and carbon monoxide are similar. Their large affinity constants for oxygen, 285 and approximately 100 micro M(-1) respectively, indicate that they are not capable of facilitating oxygen transport.

Complex signatures of selection and gene conversion in the duplicated globin genes of house mice

Results of electrophoretic surveys have suggested that hemoglobin polymorphism may be maintained by balancing selection in natural populations of house mice, Mus musculus. Here we report a survey of nucleotide variation in the adult globin genes of house mice from South America. We surveyed nucleotide polymorphism in two closely linked alpha-globin paralogs and two closely linked beta-globin paralogs to test whether patterns of variation are consistent with a model of long-term balancing selection. Surprisingly high levels of nucleotide polymorphism at the two beta-globin paralogs were attributable to the segregation of two highly divergent haplotypes, Hbbs (which carries two identical beta-globin paralogs) and Hbbd (which carries two functionally divergent beta-globin paralogs). Interparalog gene conversion on the Hbbs haplotype has produced a highly unusual situation in which the two paralogs are more similar to one another than either one is to its allelic counterpart on the Hbbd haplotype. Levels of nucleotide polymorphism and linkage disequilibrium at the two beta-globin paralogs suggest a complex history of diversity-enhancing selection that may be responsible for long-term maintenance of alternative protein alleles. The alternative two-locus beta-globin haplotypes are associated with pronounced differences in intraerythrocyte glutathione and nitric oxide metabolism, suggesting a possible mechanism for selection on hemoglobin function.

Structural Determinants in the Group III Truncated Hemoglobin from Campylobacter jejuni

Truncated hemoglobins (trHbs) constitute a distinct lineage in the globin superfamily, distantly related in size and fold to myoglobin and monomeric hemoglobins. Their phylogenetic analyses revealed that three groups (I, II, and III) compose the trHb family. Group I and II trHbs adopt a simplified globin fold, essentially composed of a 2-on-2 alpha-helical sandwich, wrapped around the heme group. So far no structural data have been reported for group III trHbs. Here we report the three-dimensional structure of the group III trHbP from the eubacterium Campylobacter jejuni. The 2.15-A resolution crystal structure of C. jejuni trHbP (cyano-met form) shows that the 2-on-2 trHb fold is substantially conserved in the trHb group III, despite the absence of the Gly-based sequence motifs that were considered necessary for the attainment of the trHb specific fold. The heme crevice presents important structural modifications in the C-E region and in the FG helical hinge, with novel surface clefts at the proximal heme site. Contrary to what has been observed for group I and II trHbs, no protein matrix tunnel/cavity system is evident in C. jejuni trHbP. A gating movement of His(E7) side chain (found in two alternate conformations in the crystal structure) may be instrumental for ligand entry to the heme distal site. Sequence conservation allows extrapolating part of the structural results here reported to the whole trHb group III.

Generation of tryptic maps of alpha- and beta-globin chains by capillary electrophoresis in isoelectric buffers

A novel method for generating peptide maps, following tryptic digests of proteins, is reported here: capillary zone electrophoresis in the presence of isoelectric buffers as the sole buffering species. A typical buffer composition comprises 50 mM aspartic acid (pH = pI = 2.77), 0.5% hydroxyethyl cellulose (added as a dynamic coating agent for preventing peptide adsorption to weakly ionized silanols), 5% trifluoroethanol and 1% zwitterionic detergent (CHAPS). With this buffer composition, a high-voltage gradient can be applied (typically 600 V/cm in 75 microns I.D. and 900 V/cm in 50 microns I.D. capillaries), thus drastically reducing the analysis times. The method is applied to the generation of peptide maps of alpha- and beta-globin chains from human adult hemoglobin. In the case of beta-peptides, at an operative pH of 2.77, which represents a cross-over point in the titration curve of peptides T2 and T9, the two analytes merge into a single peak. However it is shown that it is possible to change the pH of the zwitterionic buffer by adjusting its concentration in solution. In 30 mM Asp (pH 3.0) or 20 mM Asp (pH 3.1) resolution of these two peptides is fully restored. Isoelectric, amphoteric buffers thus seem to represent a novel, powerful buffer system able to offer high resolution and high selectivity.

Capillary electrophoresis of hemoglobin

Capillary electrophoresis (CE) has been used in a variety of in-house capillary isoelectric focusing (CIEF) and capillary zone electrophoresis (CZE) assays for the detection of hemoglobin (Hb) variants and the quantitation of HbA2 and HbF. A commercial kit has also been produced for the analysis of hemoglobin variants and thalassemia screening. Though CE methods have been shown to be able to detect many variants, final identification of the variant needs specialized testing such as DNA technology. Over the past 2 years, many instruments that had been used for these hemoglobin variant screening and thalassemia assays have been withdrawn from sale. Although CE HbA1c analysis is available, it cannot compete in turnaround time or cost with automated HPLC commercial instruments that give accurate HbA1c results in 3 or 4 minutes. Hence we do not anticipate a bright future for the analysis of hemoglobin by CE.

The nerve hemoglobin of the bivalve mollusc Spisula solidissima: molecular cloning, ligand binding studies, and phylogenetic analysis

Members of the hemoglobin (Hb) superfamily are present in nerve tissue of several vertebrate and invertebrate species. In vertebrates they display hexacoordinate heme iron atoms and are typically expressed at low levels (microM). Their function is still a matter of debate. In invertebrates they have a hexa- or pentacoordinate heme iron, are mostly expressed at high levels (mM), and have been suggested to have a myoglobin-like function. The native Hb of the surf clam, Spisula solidissima, composed of 162 amino acids, does not show specific deviations from the globin templates. UV-visible and resonance Raman spectroscopy demonstrate a hexacoordinate heme iron. Based on the sequence analogy, the histidine E7 is proposed as a sixth ligand. Kinetic and equilibrium measurements show a moderate oxygen affinity (P(50) approximately 0.6 torr) and no cooperativity. The histidine binding affinity is 100-fold lower than in neuroglobin. Phylogenetic analysis demonstrates a clustering of the S. solidissima nerve Hb with mollusc Hbs and myoglobins, but not with the vertebrate neuroglobins. We conclude that invertebrate nerve Hbs expressed at high levels are, despite the hexacoordinate nature of their heme iron, not essentially different from other intracellular Hbs. They most likely fulfill a myoglobin-like function and enhance oxygen supply to the neurons.

Oxidation of hemoglobin to methemoglobin in intact erythrocyte by a hydroperoxide induces formation of glutathionyl hemoglobin and binding of alpha-hemoglobin to membrane

Biochemical consequences of oxidation of hemoglobin (Hb) in intact human erythrocytes were studied. The incubation of washed erythrocyte with 1mM tert-butylhydroperoxide induced an increase in glutathionyl-Hb (G-Hb). The formation of G-Hb occurred linearly until 10 min in parallel with the formation of methemoglobin (metHb) after exhaustion of reduced glutathione. The results show that metHb, but not normal Hb, reacts with oxidized glutathione to form G-Hb. G-Hb was confirmed by immunoblotting with anti-glutathione antibody and the formation of G-Hb was accompanied by parallel decrease in beta-globin detected with a reversed phase HPLC. Electrophoretic studies showed time-dependent increase in membrane-associated alpha-Hb until 10 min, indicating that a part of unpaired alpha-Hb bound to the membrane. Pre-beta-globin increased despite the decrease in beta-globin and a part of the increase was independent of the decrease in beta-globin. Pre-beta-globin reacted with anti-glutathione antibody, but it differs from G-Hb in many features.

Haemoglobin Belfast 15 (A12) tryptophan leading to arginine: a new unstable haemoglobin variant

A new unstable haemoglobin, alpha(2)beta(2)15 Trp--> Arg (Hb Belfast), with increased oxygen affinity has been found during the routine investigation of a long-stay psychiatric patient. It seemed to cause little haematological disorder. The reticulocytes synthesized normal and abnormal beta-chains at the same rate but in the circulating blood Hb Belfast amounted to only 27.5% of the total haemoglobin.

Rapid screening for glucose-6-phosphate dehydrogenase deficiency and haemoglobin polymorphisms in Africa by a simple high-throughput SSOP-ELISA method

BACKGROUND

Mutations in the haemoglobin beta-globin (HbB) and glucose-6-phosphate dehydrogenase (G6PD) genes cause widespread human genetic disorders such as sickle cell diseases and G6PD deficiency. In sub-Saharan Africa, a few predominant polymorphic variants of each gene account for a majority of these deficiencies. Examining at a larger scale the clinical importance of these independent genetic disorders, their possible association with malaria pathogenesis and innate resistance, and their relevance for antimalarial drug treatment, would be easier if an accurate screening method with limited costs was available.

METHODS

A simple and rapid technique was developed to detect the most prominent single nucleotide polymorphisms (SNPs) in the HbB and G6PD genes. The method is able to detect the different haemoglobin polymorphisms A, S, C and E, as well as G6PD polymorphisms B, A and A- based on PCR-amplification followed by a hybridization step using sequence-specific oligonucleotide probes (SSOPs) specific for the SNP variants and quantified by ELISA.

RESULTS

The SSOP-ELISA method was found to be specific, and compared well to the commonly used PCR-RFLP technique. Identical results were obtained in 98% (haemoglobin) and 95% (G6PD) of the tested 90 field samples from a high-transmission area in Tanzania, which were used to validate the new technique.

CONCLUSION

The simplicity and accuracy of the new methodology makes it suitable for application in settings where resources are limited. It would serve as a valuable tool for research purposes by monitoring genotype frequencies in relation to disease epidemiology.

Ancestral hemoglobin switching in lampreys

A very simple hemoglobin switching was discovered in the lamprey Lampetra zanandreai. A single larval globin cDNA and two adult globin cDNAs were fully sequenced and their differential expression during lamprey development was investigated. The evolutionary positions of these new globin sequences are also discussed.

Occurrence of two architectural types of hexagonal bilayer hemoglobin in annelids: comparison of 3D reconstruction volumes of Arenicola marina and Lumbricus terrestris hemoglobins

A 3D reconstruction at 25 A resolution of native hemoglobin of the polychaete worm Arenicola marina was carried out from frozen-hydrated specimens examined in the electron microscope. The reconstruction volume of this large extracellular multimeric respiratory pigment appears as a hexagonal bilayer structure with eclipsed vertices in its upper and lower hexagonal layers. Conversely, in hemoglobins of oligochaetes, achaetes, and vestimentiferans and in chlorocruorins of the Sabellidae (polychaete) family, the vertices of the upper layer are 16 degrees clockwise rotated with respect to those of the lower layer. The fact that two other polychaete hemoglobins (Alvinella pompejana and Tylorrhynchus heterochaetus) have the same architecture as Arenicola led us to define two types of hexagonal bilayer hemoglobins/chlorocruorins: (i) type-I present in oligochaete, achaete, and vestimentiferan hemoglobins and in Sabellidae chlorocruorins; and (ii) type-II present in polychaete hemoglobins. A comparative study of the hemoglobins of Lumbricus terrestris (type-I) and Arenicola marina (type-II) showed that only two small differences located in the c4 and c5 linking units are responsible of the important architectural difference present in oligomers. A likely scheme proposed to explain the phylogenic distribution of the two types suggests that Clitellata, Sabellida (polychaete), and vestimentiferan hemoglobins and chlorocruorins derive from a type-I ancestral molecule, while Terebellida (Alvinella), Phyllodocida (Tylorrhynchus), and Scolecida (Arenicola) and possibly other polychaetes derive from an ancestor molecule with type-II hemoglobin. The architectures of the hollow globular substructures are highly similar in Arenicola and Lumbricus hemoglobins, with 12 globin chains and three linking units (c3a, c3b, and c4). The central piece of Arenicola hemoglobin is an ellipsoid while that of Lumbricus is a toroid. No phylogenic correlation could be found between the structure of the central pieces and the architecture type.

Associations of subtypes of hemoglobin with delta-aminolevulinic acid dehydratase genotype and dimercaptosuccinic acid-chelatable lead levels

Hemoglobin in erythrocytes may be an important intravascular site of lead binding. We examined associations of hemoglobin subtypes A1 and A2 with delta-aminolevulinic acid dehydratase (ALAD) genotype, a protein that is another important site of erythrocyte lead binding. After oral administration of dimercaptosuccinic acid (DMSA-chelatable lead), we also examined 4-h lead excretion, which provides an estimate of bioavailable lead stores. We randomly selected 57 South Korean current lead battery manufacturing workers from two plants (N = 290 employees) and from two ALAD genotype strata (ALAD1-1 and ALAD1-2). These workers voluntarily administered 5 mg/kg oral DMSA. We frequency-matched subjects with ALAD1-1 (n = 38) to subjects with ALAD1-2 (n = 19) with respect to duration of employment in the lead industry. Blood lead levels ranged from 11 to 53 microg/dl (mean +/- standard deviation, 25.4 +/- 10.2 microg/dl). After administration of oral DMSA, workers excreted a mean lead level of 85.4 (standard deviation, 45.0 microg; range, 16.5-184.1 microg). Hemoglobin A1 and A2 ranged from 3.7% to 9.9% and 1.6% to 5.9%, respectively (mean +/- standard deviation, 6.2 +/- 1.0% and 2.7 +/- 0.8%, respectively). Subjects with ALAD1-1 had elevated mean hemoglobin A1 levels (adjusted p = .05). In addition, higher hemoglobin A1 levels were associated with higher DMSA-chelatable lead levels (adjusted p = .03). This, as well as the results of prior research, suggest that both ALAD and hemoglobin A1 may be important lead-binding sites that influence urinary lead excretion after administration of DMSA.

"Bottom-up" in situ proteomic differentiation of human and non-human haemoglobins for forensic purposes by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry

RATIONALE

The detection and identification of human blood on crime-related items are of particular relevance to many investigations because shed blood can provide evidence of violent contact between individuals. However, for any detection and identification technique, specificity is a critical performance characteristic to assess; that is, whether the technique has the capability to differentiate between human blood (which usually is of relevance to a criminal investigation) and non-human blood (which usually would not be associated with a crime but may be detected incidentally).

METHODS

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) approaches using "top-down" (detection of intact proteins) and "bottom-up" (detection of tryptic peptide markers) were used to detect and identify haemoglobin in blood from humans and from a range of Australian native mammals; the technique could be carried out directly on blood stains without the need to extract proteins (i.e., in situ measurement). Imaging of haemoglobin was achieved in bloodied fingermarks, including those that had been enhanced using two "industry standard" fingermark enhancement processes.

RESULTS

Differentiation of intact haemoglobin proteins in human and non-human blood using "top-down" MALDI-TOF-MS was difficult. However, in situ "bottom-up" approaches using tandem mass spectrometry (MS/MS) and de novo sequencing of tryptic digest peptides allowed unambiguous differentiation. Imaging mass spectrometry of human haemoglobin, even when it was mixed with animal blood, was achieved in bloodied fingermarks that had been enhanced using two common processes (staining with Amido Black or dusted with magnetic powder) and "lifted" using adhesive tape.

CONCLUSIONS

The MALDI-TOF-MS-based in situ "bottom-up" proteomic methodology described here shows great promise for the detection of human blood and even imaging of blood in bloodied fingermarks. The approach is sensitive, can differentiate between human blood and that from many animals (including several Australian native animals), and can be implemented after traditional crime scene fingermark enhancement techniques have been carried out.

Relationships between hemoglobin type and reproduction, lamb, wool and milk production and health-related traits in crossbred ewes

Relationships among hemoglobin (Hb) types and production traits were examined in 294 crossbred ewes from North Country Cheviot, Dorset, Finnsheep and Romney rams, and Suffolk and Columbia-type ewes. Hb BB ewe lambs were youngest at first estrus, while Hb AA ewe lambs were oldest. Ewe lamb fertility was similar for Hb AB and Hb BB ewes, and both were superior to Hb AA ewes. When Finnsheep crossbreds were excluded, from which Hb BB was absent, Hb BB ewes had higher ewe lamb fertility than did Hb AB ewes. There was a minor advantage of the A over the B allele in ewe lamb prolificacy. Hb BB ewes were highest, Hb AB ewes were intermediate and Hb AA ewes were lowest for average fertility, prolificacy per ewe lambing, lambs born per ewe exposed to mating, total number of lambs weaned and total kilograms of lamb weaned. Grease wool production, staple length, fiber diameter grade, incidence of medullated fibers and incidence of cotted fleeces all were similar across Hb types. Likewise, Hb type did not affect milk production or composition. Ewes with Hb AB had the lowest incidence of footrot; Hb AA and Hb BB ewes were similar. Ewes with Hb AA had the lowest fecal parasite egg counts, while ewes with Hb AB or Hb BB were similar. Ewes with Hb AA also had the lowest incidence of mastitis, Hb BB ewes were intermediate and Hb AB ewes were highest. The combination of overdominance (as for footrot resistance), beneficial effects of the A allele on health-related traits (as for mastitis and parasite resistance) and the beneficial effect of the B allele on reproductive traits, if real, could partly explain the genetic polymorphism commonly reported at the Hb locus in sheep.

The multigenic family of the extracellular hemoglobin from the annelid polychaete Arenicola marina

The extracellular hemoglobin of the lugworm Arenicola marina which inhabits on the intertidal area, a sulfide-rich environment, comprises eight globin chains previously determined by mass spectrometry. We have cloned and sequenced five of the globin components. The deduced amino-acid sequences exhibit an extracellular signal peptide and two cysteine residues involved in an internal disulfide bond. The molecular weights calculated from the globin primary structures obtained from complete cDNA sequences are in good agreement with the mass spectrometry values obtained with the native hemoglobin. Phylogenetic analysis has allowed assigning the five A. marina sequences to the different globin sub-families. Two of the globins were found to be A2 globin chains lacking the cysteine residues proposed to be involved in the binding of hydrogen sulfide by such hemoglobin. We discuss the unusual absence of these cysteines in the light of their invariant occurrence in the A2 subfamily of hemoglobins from annelids inhabiting sulfide-rich environments.

Aseptic necrosis of the femoral head in sickle-cell disease

Aseptic necrosis of the femoral head accounted for 75 (28.2%) of the 266 major skeletal complications seen in 207 patients with sickle-cell disease in a 66-month period. Forty-five (60%) of the 75 patients were males. The onset of symptoms occurred between the ages of 10 and 29 years in 60 (80.0%) of the patients, and the mean age at onset was 20.8 (range 8-54) years. There were 37 patients with sickle-cell anaemia (SS) with 46 hips affected by necrosis, and 38 patients with sickle-cell haemoglobin C with 40 affected hips. Perthes-like changes occurred in 40 hips, osteochondritis dissecans-like lesion in one hip and severe hip deformity in 45 hips. Four of the five hips with Perthes-like necrosis which were treated by rotation upper femoral osteotomy had partial reconstitution of the femoral head, and all five were symptom-free. The other hips were treated conservatively with generally poor results.