C57bl 6ncrslc

All the animal experiments performed in this study were approved by the ethics committee of Chiba University based on their internal guidelines. Genetically heterogeneous four-way cross mice were produced at Chiba University as described previously [24 (link)]. The background mouse strains, BALB/cCrScl, C57BL/6NCrSlc, and CB6F1/Slc (F1 hybrid between female BALB/cCrScl and male C57BL/6NCrSlc), were obtained from Japan SLC Inc. (Shizuoka, Japan). We first mated male DBA/2CrSlc with female C3H/HeSlc to obtain F1 hybrid C3D2F1/CU. We then mated male C3D2F1/CU with female CB6F1/Slc to produce genetically heterogeneous mice (Supplementary Figure S1). Mice were weaned at 4 weeks of age and then housed in a plastic cage at 5–6 mice/cage under a 12 h light–dark cycle at room temperature. Mice were given free access to water with a plastic bottle and fed an MF pellet diet (Oriental Yeast Co., Ltd., Tokyo, Japan) ad libitum.

B6 (C57BL/6NCrSlc) and B6D2F1 ([C57BL/6NCrSlc × DBA/2CrSlc]F1) mice were purchased from Japan SLC. ICR mice were purchased from CLEA Japan Inc. Wild-derived mouse strains, CASP/1Nga (M. m. castaneus, RBRC03108, Fig. 1A) and CAST/Ei (M. m. castaneus, RBRC00733, Fig. 1B) were provided by RIKEN BRC. Female C.B-17/Icr-scid/scidJcl mice (SCID mice, CLEA Japan Inc., Tokyo, Japan) were used as the hosts for transplantation in the teratoma formation assay. Animals were provided with water and commercial laboratory mouse chow ad libitum and were housed under a controlled lighting condition (daily light from 07:00 to 21:00). For euthanasia, cervical dislocation was performed by trained individuals. Prior to the operation, mice were deeply anesthetized by intraperitoneal injection of tribromoethyl alcohol (avertin) or a mixture of three types of anesthetic agents (medetomidine, midazolam and butorphanol). They were maintained under specific pathogen-free conditions. The care and use of animals in this study were performed according to the guidelines for the use and maintenance of experimental animals from the Japanese Ministry of Environment. All animal experiments included in this study were approved by the Institutional Animal Care and Use Committee of RIKEN Tsukuba Branch. This study is reported in accordance with ARRIVE guidelines (https://arriveguidelines.org).

All animal experiments were performed strictly in accordance with protocols
approved by the Institutional Animal Care and Use Committee of AIST, NTU, Shin
Nippon Biomedical Laboratories, and Primetech. Five-week-old female mice
(Average weight=15 g, N=5;
C57BL/6NCrSlc; Japan SLC, Shizuoka, Japan) were anaesthetized with isoflurane
(2 l min⁻¹) via an automated
inhalation anaesthesia apparatus (KN-1,071; Natsume, Tokyo, Japan). Suspensions
(300 μl; LM nanocapsule and PBS buffer; LM
concentration=10 and
320 mg ml⁻¹) were injected
into caudal vein of mice. Following the injections of LM nanocapsules (LM
nanocapsule in distilled water and PBS buffer without LM nanocapsules), the
viability and body weight of mice were carefully checked for 19 days.