Morphological and molecular phylogenetic characteristics of dwarf <i>Sus</i> specimens from the Noguni shell middens in the Ryukyu Islands

Abstract

We analyzed the morphological and molecular phylogenetic characteristics of Sus bone and tooth specimens excavated from the Noguni shell midden and the Noguni B shell midden (c. 7200-4400 uncal. BP), in Okinawa main island. They were compared with those of Sus remains from later sites on the Okinawa Islands (c. 4800-1400 uncal. BP) as well as modern Ryukyu wild boar (Sus scrofa riukiuanus). Based on the length and breadth of lower third molars, Sus specimens from the Noguni shell middens were distinctly smaller than those from modern Ryukyu wild boar. Lower third molars from the Noguni shell middens also show a different size range from those of other ancient sites in the Okinawa Islands. Some haplotypes from the Noguni B shell midden belong to a different cluster from modern Ryukyu wild boar based on the analysis of mitochondrial DNA D-loop region, although nucleotide sequences are fragmentary. The morphological and molecular phylogenetic analyses indicate that Sus from the Noguni shell middens included different populations from modern Ryukyu wild boar. We suggest two possible hypotheses: first, the Sus from the Noguni shell middens were introduced to Okinawa main island from elsewhere; second, prehistoric wild boar that inhabited the Ryukyu Islands had a larger morphological and genetic variability than modern Ryukyu wild boar.

Maternal lineage of Okinawa indigenous Agu pig inferred from mitochondrial DNA control region

“…The sequences of the mtDNA control region from 30 pigs were obtained from the National Center for Biotechnology Information (NCBI) database (GenBank) (Table 1): 11 indigenous pigs from China, 4 pigs from Taiwan, 1 pig from Korea, 3 Japanese wild boars ( Sus scrofa leucomystax ), 5 Ryukyu wild boars ( Sus scrofa riukiuanus ) and 6 domestic pigs from Europe. Furthermore, the haplotypes of the Agu pig identified in this study were compared with five ancient mtDNA haplotypes unearthed at archaeological sites (7200–1700 years before the present; BP) on Okinawa Islands [6,7] (NCBI GenBank; Table 2). The five Ancient haplotypes have been classified into East Asian domestic pigs by phylogenetic analysis [6,7].…”

“…Although the details of the origins of the Agu are not yet understood, It is generally believed that the ancestors of the Agu pig were introduced from the Asian continent in the latter half of the 14th century when the ancient Kingdom of Okinawa began to trade with China [4,5]. Nonetheless, recent studies on ancient mitochondrial DNA (mtDNA) from bones excavated at archaeological sites have suggested that the introduction of domestic pigs to Okinawa from the Asian continent dates back to prehistoric times [6,7].…”

Size and shape variation of mandible and mandibular teeth in the Ryukyu wild boar (Sus scrofa riukiuanus)

“…In the present study, both Tokunoshima and Kakeroma populations exhibited a high percentage of convex bases in mandibles, commonly observed in domestic breeds (Anezaki, 2004). Since ancient times, transporting animals from one area to another is not a rare occurrence (e.g., Watanobe et al, 2002 ;Takahashi et al, 2012), and they may have been introduced from Okinawa to be kept and consumed. Genetic contamination of the indigenous population by introduced Sus is a serious concern today (Kurosawa, 1996).…”

“…Ryukyu wild boars show a large geographic variability in their size and also in their morphology. Morphological and genetic studies on different populations of Ryukyu wild boar have been published (Hayashida, 1960 ;Senba, 1964 ;Imaizumi, 1973 ;Hayashi, 1975 ;Kawashima et al, 1982 ;Hayashi et al, 1983 ;Kurosawa et al, 1986 ;Kurosawa and Tanaka, 1988 ;Endo et al, 1994Endo et al, , 1998aEndo et al, , b, 2000Endo et al, , 2002Watanobe et al, 1999 ;Takahashi et al, 2012). These studies demonstrated that the body size of Ryukyu wild boars is small compared to the Japanese wild boar (Sus scrofa leucomystax), the subspecies distributed in mainland Japan.…”

Detection of Inobuta From Wild Boar Population in Japan by Genetic Analysis

“…To verify these possibilities, it seems effective that genetic analyses that treat samples derived from both present and past periods, such as those by Nagata et al (2009) are needed. Furthermore, ancient DNA analyses of Sus scrofa bone that excavated from archaeological sites has been carried out in Japan Takahashi et al, 2012). Genetic information from these ancient DNA analyses is also useful for identification of native population of wild boar in each locality of Japan.…”