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106 | Paldurai and Samal

These differences in genome structure agree with the results
APMVs from genus Metaavulavirus of the antigenic analysis by cross-HI and cross-neutralization
tests and suggesting that these four APMV-2 strains represent
APMV-2 a single serotype with two subgroups based on antigenic
The first isolation of APMV-2 (AMAvV-2) was in Yucaipa, and genetic analysis (Subbiah et al., 2010a). A phylogenetic
California in 1956, from a diseased chicken (Gallus gallus analysis of APMV-2 strains is shown in Fig. 3.12.
domesticus) that was also infected with infectious laryngotra-
cheitis virus (Bankowski et al., 1960). Since then many Murayama virus
APMV-2 strains have been isolated worldwide. APMV-2 Murayama virus was a paramyxovirus isolated from the imported
strains are enzootic in passerines. APMV-2 has a much cynomolgus monkeys (Macaca fascicularis) in Murayama, Japan
wider host spectrum that includes turkeys, chickens and feral in 1977 and it was serologically closely related to APMV-2
birds. APMV-2 infection is more prevalent in turkeys than (Nishikawa et al., 1977a). The absence of antibodies to Muray-
in chickens (Bankowski et al., 1968). APMV-2 strains that ama virus in most monkeys of the same batch and detection of
occur worldwide display considerable antigenic and genetic similar virus in the exotic pet birds imported together in the
diversity. APMV-2 grows in wide variety of cell types with same aeroplane suggested that cynomolgus monkeys may not
or without exogenous protease supplementation. The general be the original host of this virus (Nishikawa et al., 1977b, 1981).
CPE observed in all cell types involved rounding and detach- Murayama virus strain 12344NT grew well in primary monkey
ment of cells and absence of syncytia formation (Subbiah et kidney cells and in embryonated chicken eggs. Murayama virus
al., 2008). The complete genome sequences of four APMV-2 caused syncytia formation in BHK-21 and Moult-4 cells. Exog-
strains are currently available (Subbiah et al., 2008, 2010a). enous protease supplementation increased virus growth in Vero
The genome of the prototype strain of APMV-2 Yucaipa is and LLC-MK2 cells but not in MDCK cells (Nishikawa et al.,
14,904 nt in length; whereas the genome lengths of APMV-2 1981). The F gene sequence revealed a putative fusion protein
strains Bangor, England and Kenya are 15,024, 14,904 and cleavage site sequence K-P-T-A-RF (Kusagawa et al., 1993),
14,916 nt, respectively. Each genome consists of six non- which is similar to APMV-2 strain Yucaipa. Phylogenetically,
overlapping genes in the order of 3′N-P/V/W-M-F-HN-L-5’, Murayama virus is closely related to recently isolated APMV-2
with a 55-nt leader at the 3′ end. The length of trailer at the viruses from China and strain Bangor than to strain Yucaipa
5′ end of strain Bangor was 173 nt, compared with 154 nt for (Fig. 3.12). Several species of mammals and birds, namely,
England, Kenya and Yucaipa. Sequence comparison of strains mouse, hamster, guinea pig, monkey, Bengalese finch, straw-
England and Kenya with strain Yucaipa showed 94.5 and 88% berry finch, quail and chicken, were susceptible to experimental
nt and 96 and 92% aa identity, respectively. Furthermore, infections with the virus as evidenced by seroconversion and
strain Bangor has a single basic aa residue (L-P-S-A-RF) positive virus isolation without showing any clinical signs.
Figure 12 However, no human serum samples were tested positive for
at the F protein cleavage site compared with the dibasic aa
(K-P-A-S-RF) found in those of the other three strains. antibodies to Murayama virus (Nishikawa et al., 1981).

APMV-2/gadwall/Kenya/3/80
51
APMV-2/chicken/England/7702/06
APMV-2/chicken/California/Yucaipa/56
100
APMV-2/chicken/China/NK/2001
APMV-2/chicken/China/F8/1999
61
APMV-2/Gouldian finch/China/F4/1998
APMV-2/finch/N.Ireland/Bangor/73
Murayama virus (D13990.1)
APMV-2/Anthus rufulus/China/Suiling/106/2013
99
APMV-2/Procarduelis nipalensis/China/Suiling/53/2013
100
APMV-2/Emberiza spodocephala/China/Daxinganling/974/2013

0.050

Figure 3.12 Phylogenetic analysis of APMV-2 strains. The evolutionary history was inferred based on the complete coding sequences of
fusion gene of 11 APMV-2 strains along with Murayama virus sequence by using the Maximum Likelihood method based on the Kimura
2-parameter model (Kimura, 1980) in MEGA7 (Kumar et al., 2016).