Research Article |
Corresponding author: Matthias Glaubrecht ( matthias.glaubrecht@uni-hamburg.de ) Academic editor: Andreas Schmidt-Rhaesa
© 2017 Matthias Glaubrecht, Marco T. Neiber.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Glaubrecht M, Neiber MT (2017) Museum specimens as Noah’s Arc of lost genes. The case of a rhinoceros from Sumatra in the Zoological Museum Hamburg. Evolutionary Systematics 1: 121-128. https://doi.org/10.3897/evolsyst.1.20172
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Understanding past and present genetic diversity, in particular in endangered species such as the rhinoceroses, is of paramount importance for a series of aspects in natural history, evolutionary systematics and conservation. As it turned out from several recent studies even in eminent museum specimens the historical context including its provenance often remains unresolved. At the same time modern molecular genetic techniques make this material more and more available also for integrative studies. With probably less than fifty extant specimens, among the Asian rhinoceroses the Javan rhinoceros, Rhinoceros sondaicus, is one of the most critically endangered mammal species, rendering also each of its rare museum specimens of great significance. We here apply available DNA isolation and sequencing techniques to a horn of a specimen housed at the Zoological Museum in Hamburg with indication as to derive from the extinct conspecific Sumatra population. In comparison with already existing mitochondrial gene fragment sequence data of Asian rhino populations, we were able to verify the identification of this particular museum specimen as of the nearly equally rare Sumatran rhinoceros, Dicerorhinus sumatrensis, instead as of the extremely rare R. sondaicus.
Asian rhinoceros, biohistory, mitochondrial gene fragment, molecular genetics, Javan rhinoceros, Rhinoceros sondaicus , Sumatran rhinoceros, Dicerorhinus sumatrensis , Centrum für Naturkunde (CeNak)
Not only people but also museum specimens have a life history that on the one hand can help to reconstruct past processes of gaining knowledge and on the other hand contribute to a currently emerging new discipline, to be dubbed biohistory; for case studies see e.g.
Untapped and underutilized for long, museum objects most recently gained a new importance in attempts to reconstruct environmental history in particular with the application of novel molecular genetic techniques. Advances in this field, in particular new protocols for isolating DNA from preserved materials and next generation sequencing, renders museum material also a kind of Noah’s Arc for lost genes as it has the potential to mirror the spectrum and assortment of biodiversity on the molecular and genetic level.
Therefore, in addition to help for example in reconstructing species’ distributions from museum records (for an example from malacology see e.g.
We here report on research into the records in the museum archives of the Zoological Museum Hamburg (ZMH), following hints of the existence of a horn of arguably the most rare and endangered Javan rhinoceros from the Indonesian island of Sumatra. Two species of Asian rhinoceros are known to exist there, viz. the Sumatran rhinoceros, Dicerorhinus sumatrensis, first described scientifically by the German naturalist Gotthelf Fischer von Waldheim (1771–1853) in the year 1814, and the Javan rhinoceros, Rhinoceros sondaicus Desmarest, 1822, originally described from a specimen found in Java (for clarification on the locus typicus see
The Javan rhinoceros R. sondaicus was formerly widely distributed in mainland Asia from the Sunderbans in Bangladesh across Myanmar, Thailand, Laos, Cambodia, Vietnam and peninsular Malaysia to the two larger Sunda islands Sumatra and Java. Described as a subspecies, R. sondaicus floweri Gray, 1868 (see
While there are no animals known to be kept in captivity of any zoo worldwide for about the last century, only very rarely specimens are available from museum collections. We are aware of only few R. sondaicus and D. sumatrensis, among them specimens in the Zoological Museum in Hamburg. Unfortunately, this museum, among other German and European collections, fell victim to a concerted theft of rhinoceros horns in June 2011. A total of five horns and skulls, respectively, of the two African species and all three Asian species of rhinoceroses were stolen, among them one specimen (ZMH 10617) of the extremely rare Javan rhinoceros, shot c. 1920 in West Java by a hunter named “von Stein”, with the horn sold by the Dutch agent H. L. Blonk to the Zoological Museum in Hamburg in July 1984, as given in the archival records of the museum (Fig.
The horns and skulls, respectively, of five rhinoceroses as presented on display in the exhibition of the Zoological Museum in Hamburg since the 1980s. Among them was also a horn of the extremely rare Rhinoceros sondaicus from West Java. The complete set of horns was stolen from this showcase in June 2011 [photograph courtesy of Harald Schliemann].
Investigation of the catalogues of the Department of Mammalogy and files in the museum archives revealed, however, that in addition a second horn labelled as originating from a R. sondaicus (ZMH S 8070) specimen was inventorized even earlier in this museum (indicated by the lower catalogue number), with a precise location given as on Sumatra (Fig.
The specimens ZMH S 8070 of the Zoological Museum Hamburg, labelled as “Rhinoceros sondaicus Demarest, 1822”, with location given as Djambi, Sumatra. [photograph courtesy of Thomas Kaiser].
Even more important, apparently no genetic information is available for the Sumatra population of the Javan rhinoceros, while in contrast DNA sequence fragments of the 12S rRNA and the non-coding D-loop are available from specimens from the highly endangered West Java population as well as from the now extinct populations in Vietnam (
Based on mtDNA sequence data it was the aim of this latter study to evaluate the genetic divergence between these two (then still extant) populations as well as the extent of genetic variation present in each population and species. As to the genetic diversity of the Javan rhinoceros they found three distinct haplotypes of considerable genetic variation, even among the very restricted population in Ujung Kulon National Park in West Java. This might reflect the originally largely fragmented range on the Southeast Asian mainland and the Sunda islands on the one hand and the re-colonization of Western Java following the volcanic eruption and destruction of Krakatau in 1883 as hypothesized by
Consequently, it is evident that in particular in rare species any museum specimen is of highest interest for molecular genetic studies. Therefore, we decided to apply DNA isolation techniques for historical material in order to look into the identification and origin of the museum material of R. sondaicus at hand.
This account is based on the examination of a horn from a putative R. sondaicus specimen (S 8070) in the collection of the Zoological Museum Hamburg (ZMH), which is an integral part of the in 2014 newly founded Centrum für Naturkunde (CeNak) of the Universität Hamburg (see
Dried tissue from two different parts of this isolated horn (ZMH S 8070) was collected in sterile 1.5 ml tubes. To avoid potential contamination as much as possible, outer adhering tissue layers were removed with sterile pincers prior to tissue collection. The tissue was then digested overnight and the DNA isolated according to the protocol for historical samples as detailed in
Partial sequences of the mitochondrial 12S rDNA were amplified by polymerase chain reaction (PCR) using the primer pair RH-12S-F (5’-GCC YAG ATG AGM CYA CCA RCT-3’;
CHROMASPRO version 1.7.1 (Technelysium, Tewantin, Australia) was used to assemble forward and reverse sequence reads and the sequences from the two different parts of the horn were checked for mismatches.
In addition to the newly generated data, all available 12S rDNA sequences for Rhinocerotidae from the previously published studies of
Locality data and GenBank accession numbers for Rhinocerotidae 12S rDNA sequences used in this study.
Taxon | Common name | Country | Locality | GenBank accession number (12S rDNA) | Reference |
Dicerorhinus s. sumatrensis | Sumatran rhinoceros | Indonesia | Riau and Bengkulu (Sumatra) | AY739616 |
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Dicerorhinus s. sumatrensis | Sumatran rhinoceros | – | Captive | FJ905816 |
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Dicerorhinus s. sumatrensis | Sumatran rhinoceros | Indonesia | Djambi (Sumatra) | MG674188 | this study |
Dicerorhinus sumatrensis harrissoni | Sumatran rhinoceros | Malaysia | Sabah (Borneo) | AY739617 |
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Coelodonta antiquitatis | Wooly rhinoceros | Russia | Yakutia, Taimylyr village, Olenyok River valley | FJ905813 |
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Rhinoceros unicornis | Indian rhinoceros | India/Nepal | Captive | AY739618 |
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Rhinoceros unicornis | Indian rhinoceros | India/Nepal | Captive | X97336 |
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Rhinoceros sondaicus | Javan rhinoceros | – | Collection of Oxford University Museum for Natural History (UK) | FJ905815 |
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Rhinoceros s. sondaicus | Javan rhinoceros | Indonesia | Ujung Kulon National Park | AY739620 |
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Rhinoceros s. amnamiticus | Javan rhinoceros | Vietnam | Cat Tien National Park | AY739619 |
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Ceratotherium simum | White rhinoceros | – | – | NC_001808 |
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Ceratotherium simum | White rhinoceros | – | – | X86942 |
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Ceratotherium s. simum | Southern white rhinoceros | South Africa | Krüger National Park | AY739623 |
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Ceratotherium s. cottoni | Northern white rhinoceros | Democratic Republic of the Congo | Garamba National Park | AY739624 |
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Ceratotherium s. cottoni | Northern white rhinoceros | Democratic Republic of the Congo | Garamba National Park | FJ608806 |
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Diceros bicornis | Black rhinoceros | – | – | AJ245721 |
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Diceros bicornis | Black rhinoceros | – | Collection of Zoological Museum, University of Copenhagen (Denmark) | FJ905814 |
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Diceros b. michaeli | Kenyan black rhinoceros | Kenya | Solio Game Reserve | AY739621 |
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Diceros b. michaeli | Kenyan black rhinoceros | Kenya | Solio Game Reserve | FJ608807 |
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Diceros b. cf. minor | Black rhinoceros | South Africa | – | AJ245721 |
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Diceros b. minor | Southern black rhinoceros | Zimbabwe | Zambezi Valley | AY739622 |
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Diceros b. minor | Southern black rhinoceros | Zimbabwe | Zambezi Valley | FJ608808 |
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The original alignment of the target 12S rDNA fragment had a length of 498 base pairs (bp). Surprisingly, it was noticed that the sequences from the study of
Maximum Likelihood (ML) and Maximum parsimony (MP) searches as well as Bayesian Inference (BI) of phylogeny were used to reconstruct phylogenetic relationships. To select an evolutionary model for the ML and BI analyses, the 12S rDNA sequence data set was analysed with PARTITIONFINDER version 1.1.1 (Lanfear et al. 2012). The Bayesian Information Criterion (BIC) was used to select among models.
Heuristic ML analyses were performed with the GARLI 2.1 (
Bayesian Inference was performed using MRBAYES version 3.2.6 (
Heuristic MP searches were conducted with PAUP* 4.0b10 (
Bootstrap support (BS) values from the MP and ML analyses as well as posterior probabilities (PP) from the BI analysis were mapped onto the BI 50% majority rule consensus tree with SUMTREES version 3.3.1, which is part of the DENDROPY 3.8.0 package (
The specimen ZMH S 8070, a conical horn of about 15 cm length, by its number indicating the inventarisation in the early 1980s in the Hamburg Zoological Museum, is labelled as “Rhinoceros sondaicus Demarest, 1822”, with location given as “Djambi, Sumatra” (Fig.
In the archives of the Department of Mammalogy we found a simple handwritten note, by the Dutch natural history agent and dealer H. L. Blonk, who sold several natural history objects to the Zoological Museum in Hamburg, stating the date October 10, 1984 for the delivery of three rhinoceroses at that time: in addition to one rhinoceros from South Africa, this note also lists one horn each from the Javan and the Sumatran rhinoceros, respectively, for both of which the same location is given as Djambi on Sumatra.
Apparently, this information was used to label the respective specimens by the then active collection technician (H. Schliemann, pers. comm.).
The sequences obtained from two different isolates from tissue adhering to the rhinoceros horn (ZMH S 8070) were identical and grouped with the Sumatran rhinoceros Dicerorhinus sumatrensis with very high support (PP: 0.99; BS (ML): 98; BS (MP): 100, Fig.
Historical distribution in Southeast Asia and origin of specimens used for molecular investigations of (A) the Javan rhinoceros (Rhinoceros sondaicus), with the only extant location on Java (1) and last extinct one in Vietnam (2), and (B) Sumatran rhinoceros (Dicerorhinus sumatrensis) with locations: 1 - Riau, Sumatra; 2 - Djambi, Sumatra; 3 - Bengkulu, Sumatra; 4 - Sabah, Borneo. Light shaded area: distribution given by
Phylogenetic tree of Rhinocerotidae based on mitochondrial sequences and habitus of Southeast Asian rhinoceroses. A: Bayesian 50% majority consensus tree based on 12S rDNA sequences. Posterior probabilities from Bayesian inference (left) and bootstrap support values (≥ 50%) from the maximum likelihood (middle) and maximum parsimony (right) analyses are indicated at the nodes. B, C: chromolithographies of the Sumatran rhinoceros (Dicerorhinus sumatrensis; B) and the Javan rhinoceros (Rhinoceros sondaicus; C), modified from
All three phylogenetic analyses recovered the monophyly of Rhinocerotidae with high support (PP: 1.00; BS (ML): 97; BS (MP): 100, Fig.
Understanding past and present genetic diversity, in particular in endangered species such as the rhinoceroses, is of great importance for a series of aspects of natural history, evolutionary systematics and conservation. However, as it turned out from several studies even in many museum specimens significant for various reasons the historical context including its provenance often remains unresolved (see Introduction for references to some case studies and discussion).
As direct access to genetic diversity of extinct populations can only be gained from historical specimens housed in natural history collections and museums, exact locality information in concert with resolved species identity becomes even more important, especially when considering the potential of molecular genetic techniques. Given that the only available studies to date, such as e.g.
Although the distribution and historical ranges of the single-horned Asian rhinoceroses overlap at least in some parts and peripheral areas, not too much information is available on sympatric occurrences. Obviously, both the Sumatran and the Javan rhinoceros co-occurred on the island of Sumatra. Thus, it did not seem unlikely in the first place for the Hamburg rhinoceroses that a specimen each from R. sondaicus and D. sumatrensis with identical locality data, viz. Djambi on Sumatra, was reported correctly for the two specimens sold to the ZMH in October 1984 by the Dutch dealer Blonk.
As it is impossible to differentiate the two Sumatran species by the size or shape or other morphological features of the horn alone, no clear-cut identification was possible for long. Thus, only molecular genetic techniques allowed to look into the identification and origin of this delicate and rare museum material.
As in the study of
Surprisingly, only a single 12S rDNA haplotype was found in the Sumatran rhinoceros so far, even the isolated populations from Sumatra and Borneo share the same haplotype with regard to this gene. Whether this is the result of a rapid range extension when sea level was low during the last glacial period or because of the existence of a widespread haplotype in the Sumatran rhinoceros, is difficult to decide because of the low number of individuals sequenced.
The importance of museum samples for the understanding of historic distribution ranges and the loss of genetic diversity is also highlighted in recent studies on the genetic diversity of the African black rhinoceros (
Considering that the Bornean subspecies of the Sumatran rhinoceros is on the verge of extinction (
We thank the former and active curators of the Mammal collection of the Zoological Museum in Hamburg, Harald Schliemann and Thomas Kaiser, respectively, for information on the catalogue system of the department. We thank two anonymous reviewers for their helpful comments on the manuscript.