Comparative cytogenetics of North Island tree wētā in sympatry

Figures & data

Figure 1 Distributions of chromosome races for the three Hemideina tree wētā species studied here. Orange = H. thoracica, yellow = H. trewicki, purple = H. crassidens. Distributions of H. thoracica chromosome races taken from Morgan-Richards & Wallis (2003). Distributions of H. crassidens chromosome races taken from Morgan-Richards (2000).

Figure 2 Variation in the relative size and centromere position of mitotic chromosomes from male tree wētā (Hemideina) from four populations. A, Individual chromosomes from each of 10 mitotic cells from two individual wētā from the same population (Hawkes Bay H. thoracica). Grey or black squares represent each wētā; B, Hemideina thoracica collected from Hawkes Bay (n = 10; grey squares) and Manawatu (n = 10; black triangles), one mitotic cell per wētā; C, Hemideina thoracica (Hawkes Bay and Manawatu; grey squares and black triangles) and H. crassidens from Manawatu (n = 10; white circles); D, Hemideina thoracica (Hawkes Bay and Manawatu; squares and triangles) and H. trewicki from Hawkes Bay (n = 13; dark grey diamonds); E, Hemideina trewicki from Hawkes Bay (dark grey diamonds) and male H. crassidens from Manawatu (white circles). Smaller chromosomes where no centromere could be identified were given an arbitrary P-value of 0.1%, with total length of the chromosome being its q-value. Representative mitotic chromosomes from: F, male H. thoracica; G, male H. crassidens; H, male H. trewicki.

Table 1 Average relative length of each chromosome in the karyotype of Hawkes Bay male Hemideina thoracica (n = 10), and the average ratio for arm lengths (q/p) provides centromere position, and nomenclature based on Levan et al. (1964). Metacentric (m 1.05–1.66); submetacentric (sm 1.67–2.99); subtelocentric (st 3.00–6.99); telocentric (t 7.00–39.00). The P-value used to assign chromosome pairs was taken from two-sample t-tests for differences between chromosomes.

Chromosome	Relative length ± SD	Ratio (q arm/p arm)	Type	Putative pair	P-value
1	10.98 ± 0.82	1.27	m
				1	0.288
2	10.55 ± 0.82	1.28	m
					0.051
3	9.88 ± 0.41	1.46	m
				2	0.304
4	9.69 ± 0.37	1.27	m
					0.008
5	9.23 ± 0.21	1.53	m
				3	0.386
6	9.11 ± 0.37	1.38	m
					0.027
7	8.68 ± 0.36	1.38	m
				4	0.019
8	8.27 ± 0.3	1.36	m
					0.006
9	7.71 ± 0.52	1.45	m	Sex Chr
					<0.001
10	2.88 ± 0.31	5.12	sm
				5	0.025
11	2.5 ± 0.34	5.33	sm
					0.173
12	2.2 ± 0.54	24.83	t
				6	0.284
13	1.95 ± 0.37	21.8	t
					0.162
14	1.72 ± 0.3	19.16	t
				7	0.777
15	1.67 ± 0.44	17.17	t
					0.548
16	1.56 ± 0.28	17.36	t
				8	0.462
17	1.45 ± 0.32	16.1	t

Table 2 Average relative length of each chromosome in the karyotype of Manawatu male Hemideina thoracica (n = 10), and the average ratio for arm lengths (q/p) provides centromere position, and nomenclature based on Levan et al. (1964). Metacentric (m 1.05–1.66); submetacentric (sm 1.67–2.99); subtelocentirc (st 3.00–6.99); telocentric (t 7.00–39.00). The P-value used to assign chromosome pairs was taken from two-sample t-tests for differences between chromosomes.

Chromosome	Relative length ± SD	Ratio (q arm/p arm)	Type	Putative pair	P-value
1	11.39 ± 0.7	1.36	m
				1	0.025
2	10.65 ± 0.65	1.32	m
					0.206
3	10.32 ± 0.42	1.27	m
				2	0.003
4	9.7 ± 0.4	1.27	m
					0.035
5	9.31 ± 0.35	1.34	m
				3	0.01
6	8.93 ± 0.26	1.23	m
					0.033
7	8.5 ± 0.48	1.38	m
				4	0.138
8	8.2 ± 0.37	1.33	m
					0.036
9	7.77 ± 0.63	1.3	m	Sex Chr
					<0.001
10	2.72 ± 0.19	32.8	?
				5	0.043
11	2.52 ± 0.21	30.5	?
					<0.001
12	2.06 ± 0.28	24.9	t
				6	0.036
13	1.78 ± 0.25	21.6	t
					0.273
14	1.64 ± 0.29	19.9	t
				7	0.485
15	1.55 ± 0.27	18.8	t
					0.556
16	1.48 ± 0.26	17.9	t
				8	0.186
17	1.4 ± 0.25	16.9	t

Table 3 Average relative length of each chromosome in the karyotype of Manawatu male Hemideina crassidens (n = 10), and the average ratio for arm lengths (q/p) provides centromere position, and nomenclature based on Levan et al. (1964). Metacentric (m 1.05–1.66); submetacentric (sm 1.67–2.99); subtelocentirc (st = 3.00–6.99); telocentric (t 7.00–39.00). The P-value used to assign chromosome pairs was taken from two-sample t-tests for differences between chromosomes.

Chromosome	Relative length ± SD	Ratio (q arm/p arm)	Type	Putative pair	P-value
1	11.24 ± 0.81	1.41	m
				1	0.049
2	10.61 ± 0.43	1.31	m
					0.073
3	10.17 ± 0.58	1.26	m
				2	0.046
4	9.63 ± 0.53	1.32	m
					0.006
5	8.82 ± 0.63	1.27	m	Sex Chr
					0.002
6	7.86 ± 0.51	1.38	m
				4	0.018
7	7.35 ± 0.34	1.33	m
					0.364
8	7.18 ± 0.46	1.42	m
				5	0.002
9	6.27 ± 0.61	1.26	m
					0.088
10	5.71 ± 0.77	1.17	m
				6	0.046
11	5.05 ± 0.6	1.29	m
					0.006
12	4.01 ± 0.85	1.25	m
				7	0.057
13	3.39 ± 0.39	1.22	m
					<0.001
14	1.47 ± 0.32	16.8	t
				8	0.179
15	1.29 ± 0.28	14.8	t

Figure 3 Karyotypes of four population samples of tree wētā (Hemideina), showing chromosome size relative to the entire genome length during mitosis, with standard error of the mean. One mitotic cell was used for measurements per individual, chromosomes were ranked by relative size for analysis. The putative sex chromosome in each karyotype is coloured light grey. A, Hemideina thoracica from Hawkes Bay (sample size; n = 9); B, Hemideina thoracica from Manawatu (n = 10); C, Hemideina crassidens from Manawatu (n = 10); D, H. trewicki from Hawkes Bay (n = 13).

Table 4 Average relative length of each chromosome in the karyotype of Hawkes Bay male Hemideina trewicki (n = 9), and the average ratio for arm lengths (q/p) provides centromere position, and nomenclature based on Levan et al. (1964). Metacentric (m 1.05–1.66); submetacentric (sm 1.67–2.99); subtelocentirc (st 3.00–6.99); telocentric (t 7.00–39.00). The P-value used to assign chromosome pairs was taken from two-sample t-tests for differences between chromosomes.

Chromosome	Relative length ± SD	Ratio (q arm/p arm)	Type	Putative pair	P-value
1	11.77 ± 0.76	1.19	m
				1	0.015
2	11.11 ± 0.5	1.14	m
					0.001
3	10.33 ± 0.58	1.15	m	Sex Chr
					<0.001
4	9.42 ± 0.54	1.22	m
				2	0.016
5	8.77 ± 0.72	1.16	m
					<0.001
6	7.43 ± 0.45	1.18	m
				3	0.003
7	6.75 ± 0.56	1.17	m
					<0.001
8	4.79 ± 0.69	1.21	m
				4	0.316
9	4.51 ± 0.7	1.29	m
					0.259
10	4.25 ± 0.43	1.19	m
				5	0.179
11	4.04 ± 0.31	1.16	m
					0.154
12	3.86 ± 0.31	1.17	m
				6	0.113
13	3.65 ± 0.32	1.22	m
					0.059
14	3.43 ± 0.26	1.2	m
				7	0.019
15	3.14 ± 0.31	1.18	m
					<0.001
16	1.45 ± 0.28	14.6	t
				8	0.193
17	1.3 ± 0.28	13.1	t

Morgan-Richards M, Wallis GP 2003. A comparison of five hybrid zones of the weta Hemideina thoracica (Orthoptera: Anostostomatidae): degree of cytogenetic variation fails to predict zone width. Evolution 57: 849–861.10.1111/j.0014-3820.2003.tb00296.x

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