Female African elephant rumbles differ between populations and sympatric social groups.

Vocalizations often vary in structure within a species, from the individual to population level. Vocal differences among social groups and populations can provide insight into biological processes such as vocal learning and evolutionary divergence, with important conservation implications. As vocal learners of conservation concern, intraspecific vocal variation is of particular interest in elephants. We recorded calls from individuals in multiple, wild elephant social groups in two distinct Kenyan populations. We used machine learning to investigate vocal differentiation among individual callers, core groups, bond groups (collections of core groups) and populations. We found clear evidence for vocal distinctiveness at the individual and population level, and evidence for much subtler vocal differences among social groups. Social group membership was a better predictor of call similarity than genetic relatedness, suggesting that subtle vocal differences among social groups may be learned. Vocal divergence among populations and social groups has conservation implications for the effects of social disruption and translocation of elephants.

African elephants address one another with individually specific name-like calls.

Personal names are a universal feature of human language, yet few analogues exist in other species. While dolphins and parrots address conspecifics by imitating the calls of the addressee, human names are not imitations of the sounds typically made by the named individual. Labelling objects or individuals without relying on imitation of the sounds made by the referent radically expands the expressive power of language. Thus, if non-imitative name analogues were found in other species, this could have important implications for our understanding of language evolution. Here we present evidence that wild African elephants address one another with individually specific calls, probably without relying on imitation of the receiver. We used machine learning to demonstrate that the receiver of a call could be predicted from the call's acoustic structure, regardless of how similar the call was to the receiver's vocalizations. Moreover, elephants differentially responded to playbacks of calls originally addressed to them relative to calls addressed to a different individual. Our findings offer evidence for individual addressing of conspecifics in elephants. They further suggest that, unlike other non-human animals, elephants probably do not rely on imitation of the receiver's calls to address one another.

Effects of social disruption in elephants persist decades after culling.

BACKGROUND: Multi-level fission-fusion societies, characteristic of a number of large brained mammal species including some primates, cetaceans and elephants, are among the most complex and cognitively demanding animal social systems. Many free-ranging populations of these highly social mammals already face severe human disturbance, which is set to accelerate with projected anthropogenic environmental change. Despite this, our understanding of how such disruption affects core aspects of social functioning is still very limited. RESULTS: We now use novel playback experiments to assess decision-making abilities integral to operating successfully within complex societies, and provide the first systematic evidence that fundamental social skills may be significantly impaired by anthropogenic disruption. African elephants (Loxodonta africana) that had experienced separation from family members and translocation during culling operations decades previously performed poorly on systematic tests of their social knowledge, failing to distinguish between callers on the basis of social familiarity. Moreover, elephants from the disrupted population showed no evidence of discriminating between callers when age-related cues simulated individuals on an increasing scale of social dominance, in sharp contrast to the undisturbed population where this core social ability was well developed. CONCLUSIONS: Key decision-making abilities that are fundamental to living in complex societies could be significantly altered in the long-term through exposure to severely disruptive events (e.g. culling and translocation). There is an assumption that wildlife responds to increasing pressure from human societies only in terms of demography, however our study demonstrates that the effects may be considerably more pervasive. These findings highlight the potential long-term negative consequences of acute social disruption in cognitively advanced species that live in close-knit kin-based societies, and alter our perspective on the health and functioning of populations that have been subjected to anthropogenic disturbance.

Enduring consequences of early experiences: 40 year effects on survival and success among African elephants (Loxodonta africana).

Growth from conception to reproductive onset in African elephants (Loxodonta africana) provides insights into phenotypic plasticity, individual adaptive plastic responses and facultative maternal investment. Using growth for 867 and life histories for 2652 elephants over 40 years, we demonstrate that maternal inexperience plus drought in early life result in reduced growth rates for sons and higher mortality for both sexes. Slow growth during early lactation was associated with smaller adult size, later age at first reproduction, reduced lifetime survival and consequently limited reproductive output. These enduring effects of trading slow early growth against immediate survival were apparent over the very long term; delayed downstream consequences were unexpected for a species with a maximum longevity of 70+ years and unpredictable environmental experiences.

Management of fetal hydrops due to maternal antibodies against a low incidence paternal red cell antigen: a novel insight from clinical practice.

A rare case of a low incidence red cell antigen causing severe fetal allo-immune red cell disease is presented. Discussion of how this can be diagnosed and successfully managed antenatally using middle cerebral artery Doppler ultrasound and maternal antibody titre levels for fetal surveillance and timing of intervention with intrauterine transfusion.

Leadership in elephants: the adaptive value of age.

The value of age is well recognized in human societies, where older individuals often emerge as leaders in tasks requiring specialized knowledge, but what part do such individuals play in other social species? Despite growing interest in how effective leadership might be achieved in animal social systems, the specific role that older leaders may play in decision-making has rarely been experimentally investigated. Here, we use a novel playback paradigm to demonstrate that in African elephants (Loxodonta africana), age affects the ability of matriarchs to make ecologically relevant decisions in a domain critical to survival-the assessment of predatory threat. While groups consistently adjust their defensive behaviour to the greater threat of three roaring lions versus one, families with younger matriarchs typically under-react to roars from male lions despite the severe danger they represent. Sensitivity to this key threat increases with matriarch age and is greatest for the oldest matriarchs, who are likely to have accumulated the most experience. Our study provides the first empirical evidence that individuals within a social group may derive significant benefits from the influence of an older leader because of their enhanced ability to make crucial decisions about predatory threat, generating important insights into selection for longevity in cognitively advanced social mammals.

The monovalent cation leak in overhydrated stomatocytic red blood cells results from amino acid substitutions in the Rh-associated glycoprotein.

Overhydrated hereditary stomatocytosis (OHSt) is a rare dominantly inherited hemolytic anemia characterized by a profuse membrane leak to monovalent cations. Here, we show that OHSt red cell membranes contain slightly reduced amounts of Rh-associated glycoprotein (RhAG), a putative gas channel protein. DNA analysis revealed that the OHSt patients have 1 of 2 heterozygous mutations (t182g, t194c) in RHAG that lead to substitutions of 2 highly conserved amino acids (Ile61Arg, Phe65Ser). Unexpectedly, expression of wild-type RhAG in Xenopus laevis oocytes induced a monovalent cation leak; expression of the mutant RhAG proteins induced a leak about 6 times greater than that in wild type. RhAG belongs to the ammonium transporter family of proteins that form pore-like structures. We have modeled RhAG on the homologous Nitrosomonas europaea Rh50 protein and shown that these mutations are likely to lead to an opening of the pore. Although the function of RhAG remains controversial, this first report of functional RhAG mutations supports a role for RhAG as a cation pore.

RhD variant caused by an in-frame triplet duplication in the RHD gene.

BACKGROUND: The RHD gene is highly polymorphic and a large number of D variants have already been detected. Several mechanisms are involved in the origin of D variants. In-frame deletions, resulting in a single-amino-acid deletion, have been described associated with RhD and RhCE variants. No in-frame duplications and/or insertions have been reported in the RH genes to date. STUDY DESIGN AND METHODS: Blood samples from a Brazilian blood donor and his sister were serologically tested with routine anti-D reagents and anti-D panels (ALBAclone advanced partial D typing kit, Alba Bioscience Limited; and D-Screen, Diagast), followed by molecular biology techniques, RHD polymerase chain reaction with sequence-specific priming and sequencing. RESULTS: Samples tested negative with routine immunoglobulin M (IgM) anti-D reagents and positive with IgG anti-D, which detect weak D cells. The pattern of results with anti-D panels did not correspond to any described before. A 3-bp in-frame duplication within Exon 1 (c.75_77dupTCT), resulting in the duplication of leucine 26 (p.Leu26dup), was identified in the two samples. CONCLUSION: We report the first RhD variant associated with a 3-bp in-frame duplication in the RHD gene, predicted to be located within the RhD protein transmembrane domain that might be expected to result in a weak-D-like phenotype, concordant with serologic findings.

Animal behaviour: elephants are capable of vocal learning.

There are a few mammalian species that can modify their vocalizations in response to auditory experience--for example, some marine mammals use vocal imitation for reproductive advertisement, as birds sometimes do. Here we describe two examples of vocal imitation by African savannah elephants, Loxodonta africana, a terrestrial mammal that lives in a complex fission-fusion society. Our findings favour a role for vocal imitation that has already been proposed for primates, birds, bats and marine mammals: it is a useful form of acoustic communication that helps to maintain individual-specific bonds within changing social groupings.

Does Social Complexity Drive Vocal Complexity? Insights from the Two African Elephant Species.

The social complexity hypothesis (SCH) for communication states that the range and frequency of social interactions drive the evolution of complex communication systems. Surprisingly, few studies have empirically tested the SHC for vocal communication systems. Filling this gap is important because a co-evolutionary runaway process between social and vocal complexity may have shaped the most intricate communication system, human language. We here propose the African elephant Loxodonta spec. as an excellent study system to investigate the relationships between social and vocal complexity. We review how the distinct differences in social complexity between the two species of African elephants, the forest elephant L. cyclotis and the savanna elephant L. africana, relate to repertoire size and structure, as well as complex communication skills in the two species, such as call combination or intentional formant modulation including the trunk. Our findings suggest that Loxodonta may contradict the SCH, as well as other factors put forth to explain patterns of vocal complexity across species. We propose that life history traits, a factor that has gained little attention as a driver of vocal complexity, and the extensive parental care associated with a uniquely low and slow reproductive rate, may have led to the emergence of pronounced vocal complexity in the forest elephant despite their less complex social system compared to the savanna elephant. Conclusions must be drawn cautiously, however. A better understanding of vocal complexity in the genus Loxodonta will depend on continuing advancements in remote data collection technologies to overcome the challenges of observing forest elephants in their dense rainforest habitat, as well as the availability of directly comparable data and methods, quantifying both structural and contextual variability in the production of rumbles and other vocalizations in both species of African elephants.

Ivory poaching and the rapid evolution of tusklessness in African elephants.

Understanding the evolutionary consequences of wildlife exploitation is increasingly important as harvesting becomes more efficient. We examined the impacts of ivory poaching during the Mozambican Civil War (1977 to 1992) on the evolution of African savanna elephants (Loxodonta africana) in Gorongosa National Park. Poaching resulted in strong selection that favored tusklessness amid a rapid population decline. Survey data revealed tusk-inheritance patterns consistent with an X chromosome­linked dominant, male-lethal trait. Whole-genome scans implicated two candidate genes with known roles in mammalian tooth development (AMELX and MEP1a), including the formation of enamel, dentin, cementum, and the periodontium. One of these loci (AMELX) is associated with an X-linked dominant, male-lethal syndrome in humans that diminishes the growth of maxillary lateral incisors (homologous to elephant tusks). This study provides evidence for rapid, poaching-mediated selection for the loss of a prominent anatomical trait in a keystone species.

Elephants classify human ethnic groups by odor and garment color.

Animals can benefit from classifying predators or other dangers into categories, tailoring their escape strategies to the type and nature of the risk. Studies of alarm vocalizations have revealed various levels of sophistication in classification. In many taxa, reactions to danger are inflexible, but some species can learn the level of threat presented by the local population of a predator or by specific, recognizable individuals. Some species distinguish several species of predator, giving differentiated warning calls and escape reactions; here, we explore an animal's classification of subgroups within a species. We show that elephants distinguish at least two Kenyan ethnic groups and can identify them by olfactory and color cues independently. In the Amboseli ecosystem, Kenya, young Maasai men demonstrate virility by spearing elephants (Loxodonta africana), but Kamba agriculturalists pose little threat. Elephants showed greater fear when they detected the scent of garments previously worn by Maasai than by Kamba men, and they reacted aggressively to the color associated with Maasai. Elephants are therefore able to classify members of a single species into subgroups that pose different degrees of danger.

Major histocompatibility complex variation and evolution at a single, expressed DQA locus in two genera of elephants.

Genes of the vertebrate major histocompatibility complex (MHC) are crucial to defense against infectious disease, provide an important measure of functional genetic diversity, and have been implicated in mate choice and kin recognition. As a result, MHC loci have been characterized for a number of vertebrate species, especially mammals;however, elephants are a notable exception. Our study is the first to characterize patterns of genetic diversity and natural selection in the elephant MHC. We did so using DNA sequences from a single, expressed DQA locus in elephants.We characterized six alleles in 30 African elephants(Loxodonta africana) and four alleles in three Asian elephants (Elephas maximus). In addition, for two of the African alleles and three of the Asian alleles, we characterized complete coding sequences (exons 1-5) and nearly complete non-coding sequences (introns 2-4) for the class II DQA loci. Compared to DQA in other wild mammals, we found moderate polymorphism and allelic diversity and similar patterns of selection; patterns of non-synonymous and synonymous substitutions were consistent with balancing selection acting on the peptides involved in antigen binding in the second exon. In addition, balancing selection has led to strong trans-species allelism that has maintained multiple allelic lineages across both genera of extant elephants for at least 6 million years. We discuss our results in the context of MHC diversity in other mammals and patterns of evolution in elephants.

New antigen in the Dombrock blood group system, DOYA, ablates expression of Do(a) and weakens expression of Hy, Jo(a), and Gy(a) antigens.

BACKGROUND: The Dombrock (Do) blood group system consists of five distinct antigens: Do(a), Do(b), Gy(a), Hy, and Jo(a). Our finding of a patient whose plasma contained a Do-related alloantibody suggested the presence of a sixth antigen. STUDY DESIGN AND METHODS: Standard hemagglutination, flow cytometry, and polymerase chain reaction (PCR)-based methods were used throughout. Protein homology modeling was used to map the amino acid change on the protein structure. RESULTS: The patient's red blood cells (RBCs) typed as Do(a-b-), Hy+(w), Jo(a+(w)), and Gy(a+(w)). The patient's plasma agglutinated RBCs with common Dombrock phenotypes. Reactivity with Hy- and Jo(a-) RBC samples was weak, and Gy(a-) RBC samples were nonreactive. DNA analysis showed the patient to be DO*793A (DO*A/DO*A), DO*323G, and DO*350C, which predicts the Do(a+b-), Hy+, and Jo(a+) phenotype, and revealed a homozygous single-nucleotide change of 547T>G in Exon 2 that is predicted to change tyrosine at Amino Acid Position 183 to aspartic acid. This missense substitution introduced a BtgZI restriction enzyme site. The sequence data were confirmed with a PCR-restriction fragment length polymorphism assay and revealed that the patient's parents and children were heterozygous DO*547T/G. Homology modeling predicted that the 183Tyr substitution by Asp altered the Cys182 environment and influenced the formation and/or stability of the Cys182-Cys231 disulfide bond. CONCLUSION: The patient's DO genes have a single-nucleotide change, which leads to the absence of the high-prevalence antigen DOYA. The absence of this antigen is associated with 183Asp and silencing of Do(a) and weakening of Gy(a), Hy, and Jo(a) antigens.

D variants at the RhD vestibule in the weak D type 4 and Eurasian D clusters.

BACKGROUND: One branch of the RHD phylogenetic tree is represented by the weak D type 4 cluster of alleles with F223V as the primordial amino acid substitution. F223V as well as a large number of further substitutions causing D variants are located at the extracellular RhD protein vestibule, which represents the entrance to the transmembraneous channel of the RhD protein. STUDY DESIGN AND METHODS: RHD and RHCE nucleotide sequences were determined from genomic DNA and cDNA. D epitope patterns were established with commercial monoclonal anti-D panels. RESULTS: The RHD alleles DOL-1 and DOL-2 had the two amino acid substitutions M170T (509T>C) and F223V (667T>G) in common. DOL-2 harbored the additional substitution L378V (1132C>G). Both alleles were observed in Africans and are probably evolutionary related. DMI carried M170I (510G>A), which differed from the DOL-typical substitution. DFW and DFL harbored the substitutions H166P (497A>C) and Y165C (494A>G). The antigen densities of DOL-1, DFL, and DFW were only moderately reduced. CONCLUSION: DOL-1 and DOL-2 belong to the weak D type 4 cluster of RHD alleles. Together with DMI, DFL, and DFW they represent D variants with amino acid substitutions located at extracellular loops 3 or 4 lining the RhD protein vestibule. These substitutions were of minor influence on antigen density while adjacent substitutions in the transmembraneous section caused weak D antigen expression. All these D variants were partial D and alloanti-D immunizations have been observed in DOL-1, DMI, and DFL carriers. The substitution at position 170 causes partial D although located deep in the vestibule.

Fine-scale population genetic structure in a fission-fusion society.

Nonrandom patterns of mating and dispersal create fine-scale genetic structure in natural populations - especially of social mammals - with important evolutionary and conservation genetic consequences. Such structure is well-characterized for typical mammalian societies; that is, societies where social group composition is stable, dispersal is male-biased, and males form permanent breeding associations in just one or a few social groups over the course of their lives. However, genetic structure is not well understood for social mammals that differ from this pattern, including elephants. In elephant societies, social groups fission and fuse, and males never form permanent breeding associations with female groups. Here, we combine 33 years of behavioural observations with genetic information for 545 African elephants (Loxodonta africana), to investigate how mating and dispersal behaviours structure genetic variation between social groups and across age classes. We found that, like most social mammals, female matrilocality in elephants creates co-ancestry within core social groups and significant genetic differentiation between groups (Phi(ST) = 0.058). However, unlike typical social mammals, male elephants do not bias reproduction towards a limited subset of social groups, and instead breed randomly across the population. As a result, reproductively dominant males mediate gene flow between core groups, which creates cohorts of similar-aged paternal relatives across the population. Because poaching tends to eliminate the oldest elephants from populations, illegal hunting and poaching are likely to erode fine-scale genetic structure. We discuss our results and their evolutionary and conservation genetic implications in the context of other social mammals.

Two MER2-negative individuals with the same novel CD151 mutation and evidence for clinical significance of anti-MER2.

BACKGROUND: MER2 (RAPH1), the only antigen of the RAPH blood group system, is located on the tetraspanin CD151. Only four examples of alloanti-MER2 are known. We report here two new examples of alloanti-MER2, in women of Pakistani and Turkish origin, one of whom showed signs of a hemolytic transfusion reaction (HTR) after transfusion of 3 units of red cells (RBCs). STUDY DESIGN AND METHODS: Standard serologic methods were used. A monocyte monolayer assay (MMA) was used to assess the potential clinical significance of one of the antibodies. All exons and flanking intronic sequences of CD151 were amplified and sequenced. A homology model for CD151 second extracellular loop (EC2) was constructed based on the crystal structure of CD81. RESULTS: RBCs of both patients did not react with alloanti-MER2, and neither of their antibodies reacted with MER2-negative RBCs. The MMA results suggested that the antibody that appeared to have caused an HTR had the potential to be clinically significant. Both patients were homozygous for a 511C>T mutation in CD151 encoding an Arg171Cys change. This change did not result in any significant structural rearrangement in the protein model. CONCLUSIONS: Two MER2-negative patients with anti-MER2 are homozygous for the same novel mutation encoding an amino acid substitution in the EC2 of CD151. One of the antibodies may have been responsible for an HTR, and crossmatch-compatible RBCs should be recommended for transfusion to patients with anti-MER2.

Blood group antibodies and their significance in transfusion medicine.

The discovery of almost universally present naturally occurring antibodies in blood plasma led to the discovery of the ABO blood group system which remains, more than 100 years later, the most important and clinically significant of all blood groups. Blood group antibodies play an important role in transfusion medicine, both in relation to the practice of blood transfusion and in pregnancy, but not all are clinically significant. Clinically significant antibodies are capable of causing adverse events following transfusion, ranging from mild to severe, and of causing hemolytic disease of the fetus and newborn following placental transfer from mother to fetus. Assessing the clinical significance of antibodies relies heavily on mode of reactivity and historical data relating to specificity; functional assays are sometimes employed. The principals of methodology for blood typing and antibody identification have changed little over the years, relying mainly on serological methods involving red cell agglutination. The recent advent of blood typing using DNA technology, although still in relative infancy, will surely eventually supersede serology. However, deciding on the clinical significance of an antibody when compatible blood is not immediately available is likely to remain as one of the most common dilemmas facing transfusion practitioners.